RBSE SS Computer Science flashcards

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

Bit and byte

A bit is a single binary digit, 0 or 1. A byte is a group of 8 bits and commonly represents one character in ASCII encoding.

Hexadecimal digits

Base-16 digits are 0-9 plus A-F, where A=10 through F=15. One hex digit represents exactly four binary bits.

Two's complement

A method of representing signed integers: invert all bits of the number and add 1. It gives one representation of zero and simplifies subtraction.

Logic gate XOR

Exclusive OR outputs 1 only when its two inputs differ, and 0 when both inputs are equal, either both 0 or both 1.

Algorithm

A finite step-by-step procedure that takes input, produces output, and terminates. It must be definite, effective, and unambiguous.

Flowchart decision symbol

A diamond shape represents a decision or condition in a flowchart, with branches for true and false outcomes leading to different paths.

Compiler versus interpreter

A compiler translates the entire source program into machine code before running it. An interpreter translates and executes statements one at a time.

Dry run

Manually tracing an algorithm or program with sample values, recording variable states after each step, to check whether the logic is correct.

Python indentation

Python uses indentation, not braces, to define code blocks. Statements at the same indentation level belong to the same block.

Python list mutability

Lists are mutable, so items can be changed, added, or removed after creation. Tuples and strings are immutable and cannot be modified in place.

Python range function

range(start, stop, step) generates integers from start up to but not including stop. With one argument it starts at 0 with step 1.

Python try-finally

The finally block always executes, whether or not an exception occurred. It is used for cleanup such as closing files.

Stack LIFO order

A stack inserts and removes items at the same end, called the top. The last item pushed is the first item popped.

Queue FIFO order

A queue inserts at the rear and removes from the front. The first item inserted is the first item removed.

Binary search requirement

Binary search works only on sorted data. It compares the target with the middle element and discards half the remaining elements each step.

Bubble sort

Bubble sort repeatedly compares adjacent elements and swaps them when out of order. Larger elements gradually move to the end of the list.

Linked list node

A node in a linked list holds a data value and a pointer to the next node. The last node points to null, marking the end.

Primary key

A primary key is a column or set of columns that uniquely identifies each row. It cannot contain duplicate or null values.

Foreign key

A foreign key is a column in one table that references the primary key of another table, enforcing referential integrity between related tables.

SQL WHERE and HAVING

WHERE filters individual rows before grouping. HAVING filters groups after GROUP BY and is used with aggregate functions.

Third normal form

A table is in 3NF when it is in 2NF and has no transitive dependency, meaning non-key columns depend only on the primary key.

DELETE versus DROP

DELETE is a DML command that removes selected rows but keeps the table. DROP is DDL and removes the table structure entirely.

OSI model layers

The seven OSI layers from bottom are Physical, Data Link, Network, Transport, Session, Presentation, and Application.

TCP versus UDP

TCP is connection-oriented, reliable, and ordered, used for web and email. UDP is connectionless and faster, used for streaming and DNS queries.

DNS purpose

The Domain Name System translates human-readable domain names into IP addresses so browsers can locate web servers on the internet.

Router versus switch

A router forwards packets between different networks using IP addresses. A switch forwards frames within one local network using MAC addresses.

CIA triad

The three core security goals: confidentiality keeps data private, integrity keeps data unaltered, and availability keeps systems accessible to users.

Phishing attack

Phishing tricks users with fake emails, messages, or websites that appear legitimate, aiming to steal passwords, OTPs, or banking details.

Symmetric encryption

Symmetric encryption uses the same secret key to encrypt and decrypt data. It is fast but requires secure key sharing between parties.

Cloud service models

IaaS provides virtual infrastructure, PaaS provides a development platform, and SaaS provides ready-to-use software over the internet.

Black-box testing

Black-box testing checks program behavior using inputs and expected outputs without examining internal code structure, focusing on functionality.

Syntax versus logic error

A syntax error breaks language rules and stops execution. A logic error runs without complaint but produces incorrect results.