UPMSP Intermediate Computer cheat sheet

Von Neumann architecture: CPU (ALU + control unit + registers), main memory, input, output; instructions and data share the same memory.

CPU cycle: fetch → decode → execute → store (write-back); the program counter holds the address of the next instruction.

Registers: PC (next instruction address), IR (current instruction), MAR (memory address), MBR/MDR (data), accumulator (ALU operand/result).

Memory hierarchy by speed and cost: registers > cache (L1/L2/L3) > RAM > SSD/HDD > optical/tape; capacity and access time increase downward.

RAM is volatile and randomly accessible; ROM is non-volatile. SRAM uses flip-flops (cache), DRAM uses capacitors needing refresh (main memory).

1 byte = 8 bits; 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, 1 TB = 1024 GB (binary prefixes).

Input devices: keyboard, mouse, scanner, mic, sensor. Output devices: monitor, printer, speaker, plotter. Both directions: touchscreen, modem, network card.

Primary memory is directly addressed by the CPU; secondary storage (HDD, SSD, pen drive) is non-volatile and accessed via controllers.

Clock speed in Hz sets cycle rate; throughput depends on cores, cache size, word length and bus width, not clock alone.

Base-b value: digits d(n-1)…d0 = Σ d(i) × b^i. Binary b=2, octal b=8, decimal b=10, hexadecimal b=16 (A=10 … F=15).

Binary→octal: group 3 bits from the right; binary→hex: group 4 bits from the right; pad with leading zeros as needed.

Decimal→base b: divide repeatedly by b, read remainders bottom-to-top; for fractions multiply repeatedly by b and read integer parts top-to-bottom.

Signed magnitude: leftmost bit is sign (0 = +, 1 = −); two representations of zero (+0, −0).

1's complement: invert all bits. 2's complement: invert all bits then add 1; range for n bits is −2^(n−1) to 2^(n−1) − 1.

Subtraction A − B = A + 2's complement of B; discard the final carry out of the sign bit.

ASCII is 7-bit (128 codes); extended ASCII is 8-bit (256 codes). Unicode (UTF-8/UTF-16) covers multilingual scripts.

BCD encodes each decimal digit in 4 bits; excess-3 adds 3 (0011) to each BCD digit; Gray code changes only one bit between successive values.

Parity bit detects single-bit errors (even/odd); checksum and CRC detect burst errors; Hamming code can correct single-bit errors.

OS roles: process management, memory management, file system management, device (I/O) management, security and user interface.

Process states: new → ready → running → waiting (blocked) → terminated; the scheduler picks from the ready queue.

Preemptive scheduling allows the OS to interrupt a running process; non-preemptive runs it to completion or block.

Scheduling metrics: turnaround time = completion − arrival; waiting time = turnaround − burst time.

FCFS is simple but causes convoy effect; SJF gives minimum average waiting time but needs burst-time knowledge; round robin uses a time quantum.

Deadlock needs four conditions simultaneously: mutual exclusion, hold and wait, no preemption, circular wait.

Paging divides memory into fixed-size frames/pages (no external fragmentation, may have internal); segmentation uses variable-size logical segments.

Virtual memory uses demand paging; a page fault occurs when the referenced page is not in RAM and must be loaded from disk.

File path types: absolute (from root, e.g. C:\Users\a.txt or /home/a) vs relative (from current directory); extensions map to file types (.txt, .docx, .jpg, .exe).

Algorithm properties: finiteness, definiteness, input, output, effectiveness. A flowchart uses standard symbols: oval (start/end), parallelogram (I/O), rectangle (process), diamond (decision).

Three control structures: sequence, selection (if/if-else/switch), iteration (while, do-while, for).

while tests the condition before the body (may run zero times); do-while tests after (runs at least once).

Variable scope: local variables exist inside a block/function; global variables are visible throughout the program.

Call by value passes a copy; call by reference passes the address so the callee can modify the caller's variable.

Recursion: a function calls itself with a smaller input and needs a base case to terminate; each call consumes stack space.

Searching: linear search is O(n); binary search needs sorted data and is O(log n).

Sorting: bubble/selection/insertion are O(n²); merge sort and heap sort are O(n log n).

Time complexity: O(1) constant, O(log n) logarithmic, O(n) linear, O(n log n), O(n²) quadratic; nested loops usually multiply their bounds.

DBMS vs file system: DBMS reduces redundancy, enforces integrity and concurrency control, and supports backup/recovery.

Relational model: relation = table, tuple = row, attribute = column, degree = number of columns, cardinality = number of rows.

Keys: super key (any unique identifier), candidate key (minimal super key), primary key (chosen candidate, NOT NULL and unique), foreign key (references another table's primary key).

SQL categories: DDL (CREATE, ALTER, DROP), DML (INSERT, UPDATE, DELETE), DQL (SELECT), DCL (GRANT, REVOKE), TCL (COMMIT, ROLLBACK).

Basic query form: SELECT columns FROM table WHERE condition GROUP BY columns HAVING condition ORDER BY column ASC|DESC;

Aggregate functions: COUNT, SUM, AVG, MIN, MAX; WHERE filters rows before grouping, HAVING filters groups after grouping.

Joins: INNER (matching rows only), LEFT/RIGHT OUTER (all rows from one side), FULL OUTER (all rows); CROSS JOIN is the Cartesian product.

Normalization: 1NF atomic values; 2NF no partial dependency on part of a composite key; 3NF no transitive dependency on non-key attributes.

ACID: Atomicity (all-or-nothing), Consistency, Isolation, Durability. A primary key cannot hold NULL; a foreign key may.

Network by size: PAN (few metres), LAN (building/campus), MAN (city), WAN (country/global); the Internet is the largest WAN.

Topologies: star (central hub/switch), bus (single backbone), ring (closed loop), mesh (redundant links, high reliability, high cost).

OSI layers top-down: Application, Presentation, Session, Transport, Network, Data Link, Physical. TCP/IP: Application, Transport, Internet, Network Access.

Protocols by layer: HTTP/FTP/SMTP/DNS (application), TCP/UDP (transport), IP/ICMP (network), Ethernet (data link).

TCP is connection-oriented and reliable (three-way handshake, acknowledgements); UDP is connectionless and faster but unreliable.

IPv4 is 32-bit dotted decimal; IPv6 is 128-bit hexadecimal. Private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

DNS maps domain names to IP addresses; DHCP assigns IP addresses automatically; NAT translates private to public addresses.

Transmission media: twisted pair, coaxial, fibre optic (highest bandwidth, immune to EMI), plus wireless (Wi-Fi, Bluetooth, satellite).

Bandwidth is capacity in bits per second; latency is delay. A hub broadcasts to all ports; a switch forwards by MAC address; a router forwards by IP address.

HTML defines structure with tags and attributes; holds metadata/title, holds visible content; headings are to .

Core HTML elements: (link), (image),

/
/
1. (lists), //

   (tables), with controls.

CSS controls presentation: selectors (element, .class, #id), properties (color, font-size, margin, padding, display); inline, internal

JavaScript adds client-side behaviour: variables, functions, events (onclick, onload), DOM manipulation; it runs in the browser, not on the server.

Client-server model: the browser sends an HTTP request; the server returns a status code and content. 200 OK, 301 moved, 404 not found, 500 server error.

HTTP is stateless; cookies and sessions maintain state. HTTPS is HTTP over TLS/SSL, giving encryption and server authentication.

URL parts: protocol://host[:port]/path?query#fragment. Static pages are pre-built files; dynamic pages are generated by server scripts (PHP, Python, JSP).

Multimedia types: text, audio, image, video, animation. Bitmap (raster) images store pixels (BMP, JPEG, GIF, PNG); vector images store geometric objects (SVG).

GIF supports 256 colours and simple animation; JPEG uses lossy compression for photos; PNG uses lossless compression with transparency. Video compression uses codecs such as MPEG/H.264.

Positive impacts: e-governance, e-learning, telemedicine, online banking, digital payments, remote work, faster communication.

Negative impacts: unemployment in some sectors, digital divide, information overload, privacy loss, cybercrime, e-waste.

Digital divide: the gap between those with reliable access to devices, connectivity and skills and those without; affected by income, location and education.

E-waste: discarded electronic devices; contains lead, mercury and cadmium; must be recycled, not dumped, to prevent soil and water contamination.

Green computing: power management, energy-efficient hardware, virtualization, responsible disposal, reduced printing.

Intellectual property: copyright (creative works), patent (inventions), trademark (brand identity); software piracy and plagiarism violate these.

IT Act 2000 (India) governs electronic records, digital signatures and cyber offences; amended in 2008 to add sections on identity theft and privacy.

Right to Information and data protection: individuals have rights over personal data; organizations must collect only what is needed and keep it secure.

Automation and AI change job types rather than only removing jobs; reskilling and digital literacy reduce negative employment effects.

Malware types: virus (attaches to files), worm (self-replicates over networks), trojan (disguised as useful), ransomware (encrypts data for payment), spyware (secretly collects data).

Phishing: fraudulent email/message/site that tricks users into revealing credentials; check sender address, URL spelling and never share OTPs or passwords.

Strong password: at least 12 characters mixing upper/lower case, digits and symbols, unique per site; a password manager helps; enable two-factor authentication.

Firewall filters network traffic by rules; antivirus detects known malware signatures and suspicious behaviour; both need regular updates.

Encryption converts plaintext to ciphertext with a key; symmetric uses one shared key, asymmetric uses a public/private key pair; digital signature verifies authenticity and integrity.

Social engineering exploits human trust (pretexting, fake calls, baiting); verify identity through an independent channel before acting.

Safe browsing: look for HTTPS and the padlock, avoid unknown downloads and public Wi-Fi for banking, keep software patched, back up data offline.

Cyber ethics: no unauthorized access, no data theft, no harassment or hate speech, respect privacy, give credit, follow the law and the platform's terms.

Report cybercrime in India on the National Cyber Crime Reporting Portal (cybercrime.gov.in) or helpline 1930; preserve evidence and change compromised passwords.

Von Neumann architecture: CPU (ALU + control unit + registers), main memory, input, output; instructions and data share the same memory.

CPU cycle: fetch → decode → execute → store (write-back); the program counter holds the address of the next instruction.

Registers: PC (next instruction address), IR (current instruction), MAR (memory address), MBR/MDR (data), accumulator (ALU operand/result).

Memory hierarchy by speed and cost: registers > cache (L1/L2/L3) > RAM > SSD/HDD > optical/tape; capacity and access time increase downward.

RAM is volatile and randomly accessible; ROM is non-volatile. SRAM uses flip-flops (cache), DRAM uses capacitors needing refresh (main memory).

1 byte = 8 bits; 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, 1 TB = 1024 GB (binary prefixes).

Input devices: keyboard, mouse, scanner, mic, sensor. Output devices: monitor, printer, speaker, plotter. Both directions: touchscreen, modem, network card.

Primary memory is directly addressed by the CPU; secondary storage (HDD, SSD, pen drive) is non-volatile and accessed via controllers.

Clock speed in Hz sets cycle rate; throughput depends on cores, cache size, word length and bus width, not clock alone.

Base-b value: digits d(n-1)…d0 = Σ d(i) × b^i. Binary b=2, octal b=8, decimal b=10, hexadecimal b=16 (A=10 … F=15).

Binary→octal: group 3 bits from the right; binary→hex: group 4 bits from the right; pad with leading zeros as needed.

Decimal→base b: divide repeatedly by b, read remainders bottom-to-top; for fractions multiply repeatedly by b and read integer parts top-to-bottom.

Signed magnitude: leftmost bit is sign (0 = +, 1 = −); two representations of zero (+0, −0).

1's complement: invert all bits. 2's complement: invert all bits then add 1; range for n bits is −2^(n−1) to 2^(n−1) − 1.

Subtraction A − B = A + 2's complement of B; discard the final carry out of the sign bit.

ASCII is 7-bit (128 codes); extended ASCII is 8-bit (256 codes). Unicode (UTF-8/UTF-16) covers multilingual scripts.

BCD encodes each decimal digit in 4 bits; excess-3 adds 3 (0011) to each BCD digit; Gray code changes only one bit between successive values.

Parity bit detects single-bit errors (even/odd); checksum and CRC detect burst errors; Hamming code can correct single-bit errors.

OS roles: process management, memory management, file system management, device (I/O) management, security and user interface.

Process states: new → ready → running → waiting (blocked) → terminated; the scheduler picks from the ready queue.

Preemptive scheduling allows the OS to interrupt a running process; non-preemptive runs it to completion or block.

Scheduling metrics: turnaround time = completion − arrival; waiting time = turnaround − burst time.

FCFS is simple but causes convoy effect; SJF gives minimum average waiting time but needs burst-time knowledge; round robin uses a time quantum.

Deadlock needs four conditions simultaneously: mutual exclusion, hold and wait, no preemption, circular wait.

Paging divides memory into fixed-size frames/pages (no external fragmentation, may have internal); segmentation uses variable-size logical segments.

Virtual memory uses demand paging; a page fault occurs when the referenced page is not in RAM and must be loaded from disk.

File path types: absolute (from root, e.g. C:\Users\a.txt or /home/a) vs relative (from current directory); extensions map to file types (.txt, .docx, .jpg, .exe).

Algorithm properties: finiteness, definiteness, input, output, effectiveness. A flowchart uses standard symbols: oval (start/end), parallelogram (I/O), rectangle (process), diamond (decision).

Three control structures: sequence, selection (if/if-else/switch), iteration (while, do-while, for).

while tests the condition before the body (may run zero times); do-while tests after (runs at least once).

Variable scope: local variables exist inside a block/function; global variables are visible throughout the program.

Call by value passes a copy; call by reference passes the address so the callee can modify the caller's variable.

Recursion: a function calls itself with a smaller input and needs a base case to terminate; each call consumes stack space.

Searching: linear search is O(n); binary search needs sorted data and is O(log n).

Sorting: bubble/selection/insertion are O(n²); merge sort and heap sort are O(n log n).

Time complexity: O(1) constant, O(log n) logarithmic, O(n) linear, O(n log n), O(n²) quadratic; nested loops usually multiply their bounds.

DBMS vs file system: DBMS reduces redundancy, enforces integrity and concurrency control, and supports backup/recovery.

Relational model: relation = table, tuple = row, attribute = column, degree = number of columns, cardinality = number of rows.

Keys: super key (any unique identifier), candidate key (minimal super key), primary key (chosen candidate, NOT NULL and unique), foreign key (references another table's primary key).

SQL categories: DDL (CREATE, ALTER, DROP), DML (INSERT, UPDATE, DELETE), DQL (SELECT), DCL (GRANT, REVOKE), TCL (COMMIT, ROLLBACK).

Basic query form: SELECT columns FROM table WHERE condition GROUP BY columns HAVING condition ORDER BY column ASC|DESC;

Aggregate functions: COUNT, SUM, AVG, MIN, MAX; WHERE filters rows before grouping, HAVING filters groups after grouping.

Joins: INNER (matching rows only), LEFT/RIGHT OUTER (all rows from one side), FULL OUTER (all rows); CROSS JOIN is the Cartesian product.

Normalization: 1NF atomic values; 2NF no partial dependency on part of a composite key; 3NF no transitive dependency on non-key attributes.

ACID: Atomicity (all-or-nothing), Consistency, Isolation, Durability. A primary key cannot hold NULL; a foreign key may.

Network by size: PAN (few metres), LAN (building/campus), MAN (city), WAN (country/global); the Internet is the largest WAN.

Topologies: star (central hub/switch), bus (single backbone), ring (closed loop), mesh (redundant links, high reliability, high cost).

OSI layers top-down: Application, Presentation, Session, Transport, Network, Data Link, Physical. TCP/IP: Application, Transport, Internet, Network Access.

Protocols by layer: HTTP/FTP/SMTP/DNS (application), TCP/UDP (transport), IP/ICMP (network), Ethernet (data link).

TCP is connection-oriented and reliable (three-way handshake, acknowledgements); UDP is connectionless and faster but unreliable.

IPv4 is 32-bit dotted decimal; IPv6 is 128-bit hexadecimal. Private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

DNS maps domain names to IP addresses; DHCP assigns IP addresses automatically; NAT translates private to public addresses.

Transmission media: twisted pair, coaxial, fibre optic (highest bandwidth, immune to EMI), plus wireless (Wi-Fi, Bluetooth, satellite).

Bandwidth is capacity in bits per second; latency is delay. A hub broadcasts to all ports; a switch forwards by MAC address; a router forwards by IP address.

HTML defines structure with tags and attributes; holds metadata/title, holds visible content; headings are to .

Core HTML elements: (link), (image),

/
/
1. (lists), //

   (tables), with controls.

CSS controls presentation: selectors (element, .class, #id), properties (color, font-size, margin, padding, display); inline, internal

JavaScript adds client-side behaviour: variables, functions, events (onclick, onload), DOM manipulation; it runs in the browser, not on the server.

Client-server model: the browser sends an HTTP request; the server returns a status code and content. 200 OK, 301 moved, 404 not found, 500 server error.

HTTP is stateless; cookies and sessions maintain state. HTTPS is HTTP over TLS/SSL, giving encryption and server authentication.

URL parts: protocol://host[:port]/path?query#fragment. Static pages are pre-built files; dynamic pages are generated by server scripts (PHP, Python, JSP).

Multimedia types: text, audio, image, video, animation. Bitmap (raster) images store pixels (BMP, JPEG, GIF, PNG); vector images store geometric objects (SVG).

GIF supports 256 colours and simple animation; JPEG uses lossy compression for photos; PNG uses lossless compression with transparency. Video compression uses codecs such as MPEG/H.264.

Positive impacts: e-governance, e-learning, telemedicine, online banking, digital payments, remote work, faster communication.

Negative impacts: unemployment in some sectors, digital divide, information overload, privacy loss, cybercrime, e-waste.

Digital divide: the gap between those with reliable access to devices, connectivity and skills and those without; affected by income, location and education.

E-waste: discarded electronic devices; contains lead, mercury and cadmium; must be recycled, not dumped, to prevent soil and water contamination.

Green computing: power management, energy-efficient hardware, virtualization, responsible disposal, reduced printing.

Intellectual property: copyright (creative works), patent (inventions), trademark (brand identity); software piracy and plagiarism violate these.

IT Act 2000 (India) governs electronic records, digital signatures and cyber offences; amended in 2008 to add sections on identity theft and privacy.

Right to Information and data protection: individuals have rights over personal data; organizations must collect only what is needed and keep it secure.

Automation and AI change job types rather than only removing jobs; reskilling and digital literacy reduce negative employment effects.

Malware types: virus (attaches to files), worm (self-replicates over networks), trojan (disguised as useful), ransomware (encrypts data for payment), spyware (secretly collects data).

Phishing: fraudulent email/message/site that tricks users into revealing credentials; check sender address, URL spelling and never share OTPs or passwords.

Strong password: at least 12 characters mixing upper/lower case, digits and symbols, unique per site; a password manager helps; enable two-factor authentication.

Firewall filters network traffic by rules; antivirus detects known malware signatures and suspicious behaviour; both need regular updates.

Encryption converts plaintext to ciphertext with a key; symmetric uses one shared key, asymmetric uses a public/private key pair; digital signature verifies authenticity and integrity.

Social engineering exploits human trust (pretexting, fake calls, baiting); verify identity through an independent channel before acting.

Safe browsing: look for HTTPS and the padlock, avoid unknown downloads and public Wi-Fi for banking, keep software patched, back up data offline.

Cyber ethics: no unauthorized access, no data theft, no harassment or hate speech, respect privacy, give credit, follow the law and the platform's terms.

Report cybercrime in India on the National Cyber Crime Reporting Portal (cybercrime.gov.in) or helpline 1930; preserve evidence and change compromised passwords.

Base-b value: digits d(n-1)…d0 = Σ d(i) × b^i. Binary b=2, octal b=8, decimal b=10, hexadecimal b=16 (A=10 … F=15).

Binary→octal: group 3 bits from the right; binary→hex: group 4 bits from the right; pad with leading zeros as needed.

Decimal→base b: divide repeatedly by b, read remainders bottom-to-top; for fractions multiply repeatedly by b and read integer parts top-to-bottom.

Signed magnitude: leftmost bit is sign (0 = +, 1 = −); two representations of zero (+0, −0).

1's complement: invert all bits. 2's complement: invert all bits then add 1; range for n bits is −2^(n−1) to 2^(n−1) − 1.

Subtraction A − B = A + 2's complement of B; discard the final carry out of the sign bit.

ASCII is 7-bit (128 codes); extended ASCII is 8-bit (256 codes). Unicode (UTF-8/UTF-16) covers multilingual scripts.

BCD encodes each decimal digit in 4 bits; excess-3 adds 3 (0011) to each BCD digit; Gray code changes only one bit between successive values.

Parity bit detects single-bit errors (even/odd); checksum and CRC detect burst errors; Hamming code can correct single-bit errors.

OS roles: process management, memory management, file system management, device (I/O) management, security and user interface.

Process states: new → ready → running → waiting (blocked) → terminated; the scheduler picks from the ready queue.

Preemptive scheduling allows the OS to interrupt a running process; non-preemptive runs it to completion or block.

Scheduling metrics: turnaround time = completion − arrival; waiting time = turnaround − burst time.

FCFS is simple but causes convoy effect; SJF gives minimum average waiting time but needs burst-time knowledge; round robin uses a time quantum.

Deadlock needs four conditions simultaneously: mutual exclusion, hold and wait, no preemption, circular wait.

Paging divides memory into fixed-size frames/pages (no external fragmentation, may have internal); segmentation uses variable-size logical segments.

Virtual memory uses demand paging; a page fault occurs when the referenced page is not in RAM and must be loaded from disk.

File path types: absolute (from root, e.g. C:\Users\a.txt or /home/a) vs relative (from current directory); extensions map to file types (.txt, .docx, .jpg, .exe).

Algorithm properties: finiteness, definiteness, input, output, effectiveness. A flowchart uses standard symbols: oval (start/end), parallelogram (I/O), rectangle (process), diamond (decision).

Three control structures: sequence, selection (if/if-else/switch), iteration (while, do-while, for).

while tests the condition before the body (may run zero times); do-while tests after (runs at least once).

Variable scope: local variables exist inside a block/function; global variables are visible throughout the program.

Call by value passes a copy; call by reference passes the address so the callee can modify the caller's variable.

Recursion: a function calls itself with a smaller input and needs a base case to terminate; each call consumes stack space.

Searching: linear search is O(n); binary search needs sorted data and is O(log n).

Sorting: bubble/selection/insertion are O(n²); merge sort and heap sort are O(n log n).

Time complexity: O(1) constant, O(log n) logarithmic, O(n) linear, O(n log n), O(n²) quadratic; nested loops usually multiply their bounds.

DBMS vs file system: DBMS reduces redundancy, enforces integrity and concurrency control, and supports backup/recovery.

Relational model: relation = table, tuple = row, attribute = column, degree = number of columns, cardinality = number of rows.

Keys: super key (any unique identifier), candidate key (minimal super key), primary key (chosen candidate, NOT NULL and unique), foreign key (references another table's primary key).

SQL categories: DDL (CREATE, ALTER, DROP), DML (INSERT, UPDATE, DELETE), DQL (SELECT), DCL (GRANT, REVOKE), TCL (COMMIT, ROLLBACK).

Basic query form: SELECT columns FROM table WHERE condition GROUP BY columns HAVING condition ORDER BY column ASC|DESC;

Aggregate functions: COUNT, SUM, AVG, MIN, MAX; WHERE filters rows before grouping, HAVING filters groups after grouping.

Joins: INNER (matching rows only), LEFT/RIGHT OUTER (all rows from one side), FULL OUTER (all rows); CROSS JOIN is the Cartesian product.

Normalization: 1NF atomic values; 2NF no partial dependency on part of a composite key; 3NF no transitive dependency on non-key attributes.

ACID: Atomicity (all-or-nothing), Consistency, Isolation, Durability. A primary key cannot hold NULL; a foreign key may.

Network by size: PAN (few metres), LAN (building/campus), MAN (city), WAN (country/global); the Internet is the largest WAN.

Topologies: star (central hub/switch), bus (single backbone), ring (closed loop), mesh (redundant links, high reliability, high cost).

OSI layers top-down: Application, Presentation, Session, Transport, Network, Data Link, Physical. TCP/IP: Application, Transport, Internet, Network Access.

Protocols by layer: HTTP/FTP/SMTP/DNS (application), TCP/UDP (transport), IP/ICMP (network), Ethernet (data link).

TCP is connection-oriented and reliable (three-way handshake, acknowledgements); UDP is connectionless and faster but unreliable.

IPv4 is 32-bit dotted decimal; IPv6 is 128-bit hexadecimal. Private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

DNS maps domain names to IP addresses; DHCP assigns IP addresses automatically; NAT translates private to public addresses.

Transmission media: twisted pair, coaxial, fibre optic (highest bandwidth, immune to EMI), plus wireless (Wi-Fi, Bluetooth, satellite).

Bandwidth is capacity in bits per second; latency is delay. A hub broadcasts to all ports; a switch forwards by MAC address; a router forwards by IP address.

HTML defines structure with tags and attributes; holds metadata/title, holds visible content; headings are to .

Core HTML elements: (link), (image),

/
/
1. (lists), //

   (tables), with controls.

CSS controls presentation: selectors (element, .class, #id), properties (color, font-size, margin, padding, display); inline, internal

JavaScript adds client-side behaviour: variables, functions, events (onclick, onload), DOM manipulation; it runs in the browser, not on the server.

Client-server model: the browser sends an HTTP request; the server returns a status code and content. 200 OK, 301 moved, 404 not found, 500 server error.

HTTP is stateless; cookies and sessions maintain state. HTTPS is HTTP over TLS/SSL, giving encryption and server authentication.

URL parts: protocol://host[:port]/path?query#fragment. Static pages are pre-built files; dynamic pages are generated by server scripts (PHP, Python, JSP).

Multimedia types: text, audio, image, video, animation. Bitmap (raster) images store pixels (BMP, JPEG, GIF, PNG); vector images store geometric objects (SVG).

GIF supports 256 colours and simple animation; JPEG uses lossy compression for photos; PNG uses lossless compression with transparency. Video compression uses codecs such as MPEG/H.264.

Positive impacts: e-governance, e-learning, telemedicine, online banking, digital payments, remote work, faster communication.

Negative impacts: unemployment in some sectors, digital divide, information overload, privacy loss, cybercrime, e-waste.

Digital divide: the gap between those with reliable access to devices, connectivity and skills and those without; affected by income, location and education.

E-waste: discarded electronic devices; contains lead, mercury and cadmium; must be recycled, not dumped, to prevent soil and water contamination.

Green computing: power management, energy-efficient hardware, virtualization, responsible disposal, reduced printing.

Intellectual property: copyright (creative works), patent (inventions), trademark (brand identity); software piracy and plagiarism violate these.

IT Act 2000 (India) governs electronic records, digital signatures and cyber offences; amended in 2008 to add sections on identity theft and privacy.

Right to Information and data protection: individuals have rights over personal data; organizations must collect only what is needed and keep it secure.

Automation and AI change job types rather than only removing jobs; reskilling and digital literacy reduce negative employment effects.

Malware types: virus (attaches to files), worm (self-replicates over networks), trojan (disguised as useful), ransomware (encrypts data for payment), spyware (secretly collects data).

Phishing: fraudulent email/message/site that tricks users into revealing credentials; check sender address, URL spelling and never share OTPs or passwords.

Strong password: at least 12 characters mixing upper/lower case, digits and symbols, unique per site; a password manager helps; enable two-factor authentication.

Firewall filters network traffic by rules; antivirus detects known malware signatures and suspicious behaviour; both need regular updates.

Encryption converts plaintext to ciphertext with a key; symmetric uses one shared key, asymmetric uses a public/private key pair; digital signature verifies authenticity and integrity.

Social engineering exploits human trust (pretexting, fake calls, baiting); verify identity through an independent channel before acting.

Safe browsing: look for HTTPS and the padlock, avoid unknown downloads and public Wi-Fi for banking, keep software patched, back up data offline.

Cyber ethics: no unauthorized access, no data theft, no harassment or hate speech, respect privacy, give credit, follow the law and the platform's terms.

Report cybercrime in India on the National Cyber Crime Reporting Portal (cybercrime.gov.in) or helpline 1930; preserve evidence and change compromised passwords.

Von Neumann architecture: CPU (ALU + control unit + registers), main memory, input, output; instructions and data share the same memory.

CPU cycle: fetch → decode → execute → store (write-back); the program counter holds the address of the next instruction.

Registers: PC (next instruction address), IR (current instruction), MAR (memory address), MBR/MDR (data), accumulator (ALU operand/result).

Memory hierarchy by speed and cost: registers > cache (L1/L2/L3) > RAM > SSD/HDD > optical/tape; capacity and access time increase downward.

RAM is volatile and randomly accessible; ROM is non-volatile. SRAM uses flip-flops (cache), DRAM uses capacitors needing refresh (main memory).

1 byte = 8 bits; 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, 1 TB = 1024 GB (binary prefixes).

Input devices: keyboard, mouse, scanner, mic, sensor. Output devices: monitor, printer, speaker, plotter. Both directions: touchscreen, modem, network card.

Primary memory is directly addressed by the CPU; secondary storage (HDD, SSD, pen drive) is non-volatile and accessed via controllers.

Clock speed in Hz sets cycle rate; throughput depends on cores, cache size, word length and bus width, not clock alone.

Base-b value: digits d(n-1)…d0 = Σ d(i) × b^i. Binary b=2, octal b=8, decimal b=10, hexadecimal b=16 (A=10 … F=15).

Binary→octal: group 3 bits from the right; binary→hex: group 4 bits from the right; pad with leading zeros as needed.

Decimal→base b: divide repeatedly by b, read remainders bottom-to-top; for fractions multiply repeatedly by b and read integer parts top-to-bottom.

Signed magnitude: leftmost bit is sign (0 = +, 1 = −); two representations of zero (+0, −0).

1's complement: invert all bits. 2's complement: invert all bits then add 1; range for n bits is −2^(n−1) to 2^(n−1) − 1.

Subtraction A − B = A + 2's complement of B; discard the final carry out of the sign bit.

ASCII is 7-bit (128 codes); extended ASCII is 8-bit (256 codes). Unicode (UTF-8/UTF-16) covers multilingual scripts.

BCD encodes each decimal digit in 4 bits; excess-3 adds 3 (0011) to each BCD digit; Gray code changes only one bit between successive values.

Parity bit detects single-bit errors (even/odd); checksum and CRC detect burst errors; Hamming code can correct single-bit errors.

OS roles: process management, memory management, file system management, device (I/O) management, security and user interface.

Process states: new → ready → running → waiting (blocked) → terminated; the scheduler picks from the ready queue.

Preemptive scheduling allows the OS to interrupt a running process; non-preemptive runs it to completion or block.

Scheduling metrics: turnaround time = completion − arrival; waiting time = turnaround − burst time.

FCFS is simple but causes convoy effect; SJF gives minimum average waiting time but needs burst-time knowledge; round robin uses a time quantum.

Deadlock needs four conditions simultaneously: mutual exclusion, hold and wait, no preemption, circular wait.

Paging divides memory into fixed-size frames/pages (no external fragmentation, may have internal); segmentation uses variable-size logical segments.

Virtual memory uses demand paging; a page fault occurs when the referenced page is not in RAM and must be loaded from disk.

File path types: absolute (from root, e.g. C:\Users\a.txt or /home/a) vs relative (from current directory); extensions map to file types (.txt, .docx, .jpg, .exe).

Algorithm properties: finiteness, definiteness, input, output, effectiveness. A flowchart uses standard symbols: oval (start/end), parallelogram (I/O), rectangle (process), diamond (decision).

Three control structures: sequence, selection (if/if-else/switch), iteration (while, do-while, for).

while tests the condition before the body (may run zero times); do-while tests after (runs at least once).

Variable scope: local variables exist inside a block/function; global variables are visible throughout the program.

Call by value passes a copy; call by reference passes the address so the callee can modify the caller's variable.

Recursion: a function calls itself with a smaller input and needs a base case to terminate; each call consumes stack space.

Searching: linear search is O(n); binary search needs sorted data and is O(log n).

Sorting: bubble/selection/insertion are O(n²); merge sort and heap sort are O(n log n).

Time complexity: O(1) constant, O(log n) logarithmic, O(n) linear, O(n log n), O(n²) quadratic; nested loops usually multiply their bounds.

DBMS vs file system: DBMS reduces redundancy, enforces integrity and concurrency control, and supports backup/recovery.

Relational model: relation = table, tuple = row, attribute = column, degree = number of columns, cardinality = number of rows.

Keys: super key (any unique identifier), candidate key (minimal super key), primary key (chosen candidate, NOT NULL and unique), foreign key (references another table's primary key).

SQL categories: DDL (CREATE, ALTER, DROP), DML (INSERT, UPDATE, DELETE), DQL (SELECT), DCL (GRANT, REVOKE), TCL (COMMIT, ROLLBACK).

Basic query form: SELECT columns FROM table WHERE condition GROUP BY columns HAVING condition ORDER BY column ASC|DESC;

Aggregate functions: COUNT, SUM, AVG, MIN, MAX; WHERE filters rows before grouping, HAVING filters groups after grouping.

Joins: INNER (matching rows only), LEFT/RIGHT OUTER (all rows from one side), FULL OUTER (all rows); CROSS JOIN is the Cartesian product.

Normalization: 1NF atomic values; 2NF no partial dependency on part of a composite key; 3NF no transitive dependency on non-key attributes.

ACID: Atomicity (all-or-nothing), Consistency, Isolation, Durability. A primary key cannot hold NULL; a foreign key may.

Network by size: PAN (few metres), LAN (building/campus), MAN (city), WAN (country/global); the Internet is the largest WAN.

Topologies: star (central hub/switch), bus (single backbone), ring (closed loop), mesh (redundant links, high reliability, high cost).

OSI layers top-down: Application, Presentation, Session, Transport, Network, Data Link, Physical. TCP/IP: Application, Transport, Internet, Network Access.

Protocols by layer: HTTP/FTP/SMTP/DNS (application), TCP/UDP (transport), IP/ICMP (network), Ethernet (data link).

TCP is connection-oriented and reliable (three-way handshake, acknowledgements); UDP is connectionless and faster but unreliable.

IPv4 is 32-bit dotted decimal; IPv6 is 128-bit hexadecimal. Private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

DNS maps domain names to IP addresses; DHCP assigns IP addresses automatically; NAT translates private to public addresses.

Transmission media: twisted pair, coaxial, fibre optic (highest bandwidth, immune to EMI), plus wireless (Wi-Fi, Bluetooth, satellite).

Bandwidth is capacity in bits per second; latency is delay. A hub broadcasts to all ports; a switch forwards by MAC address; a router forwards by IP address.

HTML defines structure with tags and attributes; holds metadata/title, holds visible content; headings are to .

Core HTML elements: (link), (image),

/
/
1. (lists), //

   (tables), with controls.

CSS controls presentation: selectors (element, .class, #id), properties (color, font-size, margin, padding, display); inline, internal

JavaScript adds client-side behaviour: variables, functions, events (onclick, onload), DOM manipulation; it runs in the browser, not on the server.

Client-server model: the browser sends an HTTP request; the server returns a status code and content. 200 OK, 301 moved, 404 not found, 500 server error.

HTTP is stateless; cookies and sessions maintain state. HTTPS is HTTP over TLS/SSL, giving encryption and server authentication.

URL parts: protocol://host[:port]/path?query#fragment. Static pages are pre-built files; dynamic pages are generated by server scripts (PHP, Python, JSP).

Multimedia types: text, audio, image, video, animation. Bitmap (raster) images store pixels (BMP, JPEG, GIF, PNG); vector images store geometric objects (SVG).

GIF supports 256 colours and simple animation; JPEG uses lossy compression for photos; PNG uses lossless compression with transparency. Video compression uses codecs such as MPEG/H.264.

Positive impacts: e-governance, e-learning, telemedicine, online banking, digital payments, remote work, faster communication.

Negative impacts: unemployment in some sectors, digital divide, information overload, privacy loss, cybercrime, e-waste.

Digital divide: the gap between those with reliable access to devices, connectivity and skills and those without; affected by income, location and education.

E-waste: discarded electronic devices; contains lead, mercury and cadmium; must be recycled, not dumped, to prevent soil and water contamination.

Green computing: power management, energy-efficient hardware, virtualization, responsible disposal, reduced printing.

Intellectual property: copyright (creative works), patent (inventions), trademark (brand identity); software piracy and plagiarism violate these.

IT Act 2000 (India) governs electronic records, digital signatures and cyber offences; amended in 2008 to add sections on identity theft and privacy.

Right to Information and data protection: individuals have rights over personal data; organizations must collect only what is needed and keep it secure.

Automation and AI change job types rather than only removing jobs; reskilling and digital literacy reduce negative employment effects.

Malware types: virus (attaches to files), worm (self-replicates over networks), trojan (disguised as useful), ransomware (encrypts data for payment), spyware (secretly collects data).

Phishing: fraudulent email/message/site that tricks users into revealing credentials; check sender address, URL spelling and never share OTPs or passwords.

Strong password: at least 12 characters mixing upper/lower case, digits and symbols, unique per site; a password manager helps; enable two-factor authentication.

Firewall filters network traffic by rules; antivirus detects known malware signatures and suspicious behaviour; both need regular updates.

Encryption converts plaintext to ciphertext with a key; symmetric uses one shared key, asymmetric uses a public/private key pair; digital signature verifies authenticity and integrity.

Social engineering exploits human trust (pretexting, fake calls, baiting); verify identity through an independent channel before acting.

Safe browsing: look for HTTPS and the padlock, avoid unknown downloads and public Wi-Fi for banking, keep software patched, back up data offline.

Cyber ethics: no unauthorized access, no data theft, no harassment or hate speech, respect privacy, give credit, follow the law and the platform's terms.

Report cybercrime in India on the National Cyber Crime Reporting Portal (cybercrime.gov.in) or helpline 1930; preserve evidence and change compromised passwords.