CHSE Odisha Elective Computer Science flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Von Neumann architecture

A design in which CPU, memory, and input/output units share a single stored-program memory; instructions and data are fetched, decoded, and executed in sequence.

Cache memory

A small, fast memory between CPU and main memory that holds recently or frequently used instructions and data, exploiting temporal and spatial locality to reduce average access time.

Operating system

System software that manages processes, memory, files, and devices, provides a user interface, and allocates resources so application programs can run efficiently.

RAM versus ROM

RAM is volatile read/write working memory that loses contents when power is off; ROM is non-volatile memory whose stored firmware or startup instructions remain without power.

Positional number system

A system in which a digit's value depends on its position relative to the radix point, computed as digit multiplied by base raised to the position index.

Two's complement

An n-bit signed representation formed by inverting all bits of a positive number and adding one; it represents negatives and allows subtraction by addition.

BCD encoding

Binary-coded decimal represents each decimal digit separately by its four-bit binary pattern, so 25 is 0010 0101 rather than the ordinary binary value.

Binary to hexadecimal

Group binary bits into fours starting at the radix point and moving outward, pad incomplete groups with zeros, then replace each group by its hexadecimal digit.

Universal logic gate

A gate, specifically NAND or NOR, from which AND, OR, and NOT functions can be built, so any Boolean circuit can be implemented using only that gate type.

De Morgan's theorems

Two Boolean identities: the complement of an OR is the AND of complements, and the complement of an AND is the OR of complements.

XOR gate

A two-input gate whose output is 1 only when the inputs differ; its Boolean expression is A'B + AB', and it is used in parity and adder circuits.

Karnaugh map

A grid arrangement of truth-table cells in Gray-code order used to simplify Boolean expressions by grouping adjacent 1s in powers of two.

Pass by value

C's default argument-passing method: the function receives copies of argument values, so changing a parameter inside the function does not alter the caller's original variable.

Null-terminated string

A C string stored as an array of characters ending with the null character '\0', which marks the end for functions such as strlen, strcpy, and printf's %s.

Pointer dereference

Applying the unary * operator to a pointer to access or modify the value stored at the address it holds; the pointer must contain a valid address.

do-while loop

A C loop that executes its body once before testing the condition; it repeats while the condition is true, so the body always runs at least one time.

Stack LIFO

A linear data structure in which insertion and deletion occur at one end called the top, so the last element pushed is the first element popped.

Circular queue

A queue implemented in an array whose rear and front indices wrap around, reusing freed positions and avoiding the false-full condition of a simple linear array queue.

Binary search requirement

Binary search works only on a sorted array; it compares the target with the middle element and discards half the remaining search interval each time.

Linked list node

A self-referential structure containing a data field and a pointer to the next node; the last node's pointer is NULL in a singly linked list.

Primary key

A column or minimal set of columns chosen to uniquely identify each row in a table; it cannot contain NULL values and only one primary key is allowed per table.

Foreign key

An attribute or attribute set in one table that references a primary or candidate key in another table, enforcing referential integrity between related rows.

Third normal form

A relation is in 3NF when it is in 2NF and every non-prime attribute depends nontransitively on every candidate key, eliminating dependencies between non-key attributes.

SQL HAVING clause

A clause that filters groups after GROUP BY has formed them; it can use aggregate functions, unlike WHERE, which filters individual rows before grouping.

OSI reference model

A seven-layer conceptual framework for network communication: physical, data link, network, transport, session, presentation, and application, each providing services to the layer above.

TCP versus UDP

TCP is connection-oriented and reliable, using acknowledgements and retransmission; UDP is connectionless and unreliable but has lower overhead, suiting streaming and DNS queries.

IP address

A numeric label assigned to a network interface for routing; IPv4 uses 32 bits written as four dotted decimal octets, while IPv6 uses 128 bits in hexadecimal.

DNS

The Domain Name System translates human-readable domain names into IP addresses through distributed hierarchical servers, enabling browsers to locate web and mail services.

HTML anchor tag

The <a> element creates a hyperlink; its href attribute gives the destination URL, and the enclosed text or image becomes the clickable link.

CSS box model

The layout model in which every element consists of content, padding, border, and margin; width and height apply to the content box unless box-sizing changes this.

Alt attribute

Text supplied in an image tag's alt attribute; it displays when the image fails to load and is read by screen readers, improving accessibility.

Lossy compression

A multimedia compression method that permanently discards some data to reduce file size greatly; JPEG images and MP3 audio are common examples.