Karnataka II PUC Computer Science (KSEAB) key terms

A computer design in which program instructions and data share the same main memory, and a single processor fetches, decodes and executes instructions one after another.

The part of a computer that fetches instructions from memory, decodes them and carries out arithmetic and logical operations; it also controls the other units using timing and control signals.

Random Access Memory is the main read/write memory that temporarily holds programs and data while the computer runs; its contents are lost when power is switched off.

Read Only Memory is non-volatile memory whose contents are written during manufacture or by special equipment; it usually stores start-up instructions needed when the computer is switched on.

A small, very fast memory placed between the processor and main memory that keeps frequently used instructions and data, reducing the average time the processor waits for memory.

The smallest unit of digital information, representing a single binary digit that is either 0 or 1; groups of bits are used to represent numbers, characters and instructions.

A group of eight bits treated as one unit; it is the basic addressable storage unit in most computers and can hold one character code or a small number.

A method of representing signed integers in binary in which the leftmost bit gives the sign; negative numbers are formed by inverting all bits and adding one.

American Standard Code for Information Interchange assigns a 7-bit numeric code to letters, digits, punctuation and control characters, allowing text to be stored and exchanged between computers.

A finite, ordered set of clear steps that solves a problem or completes a task; each step must be unambiguous, and the process must terminate after a limited number of operations.

A diagram that represents an algorithm using standard symbols such as ovals for start and end and diamonds for decisions, with arrows showing the order of execution.

A structured, English-like description of an algorithm that uses programming constructs such as IF and WHILE without following the strict syntax of any particular language.

A translation program that reads a complete source program written in a high-level language and produces machine code or object code, reporting syntax errors before the program is run.

A programming approach that organises a program around objects, which combine data and the functions that operate on that data, and around classes that describe those objects.

A specification of the kind of values a variable can hold and the operations allowed on them, such as int for whole numbers, float for real numbers and char for single characters.

The rules that decide which operator in an expression is evaluated first when several are used without brackets; for example, multiplication is performed before addition.

A control structure such as if, if-else or switch that tests a condition and chooses which statements to execute, so the program can take different paths.

A collection of a fixed number of elements of the same data type, stored in consecutive memory locations and accessed by a common name with an index.

An array whose elements are arranged in rows and columns and are accessed with two indices, often used to store tables or matrices.

A declaration that tells the compiler a function's name, return type and parameter types before the function is defined or called, allowing type checking.

A way of passing arguments in which the function receives the address of the original variable, so changes made inside the function affect the caller's variable.

A user-defined data type that groups variables of different data types under one name, so related information about a single item can be stored together.

A user-defined type that bundles data members and member functions into one unit; it acts as a blueprint from which objects are created.

An individual instance of a class that has its own copy of the data members and can use the member functions defined by the class.

A special member function with the same name as its class that is called automatically when an object is created, usually to initialise the object's data members.

A constructor that can be called with no arguments; if a class declares no constructor at all, the compiler supplies one automatically.

Giving an existing C++ operator such as + or << a new meaning for objects of a class, so the operator can work with user-defined types in a natural way.

A feature in which a new class acquires the data members and member functions of an existing class and may add or modify behaviour of its own.

A class created from another class, called its base class; it inherits the base class members and can add new members or redefine inherited functions.

A variable that stores the memory address of another variable or object, allowing indirect access to data and enabling dynamic data structures.

Allocating memory while a program runs, using operators such as new in C++, so the size of a data structure can be decided at execution time rather than at compile time.

An object that connects a program to a disk file for input or output, providing operations such as opening, reading, writing and closing the file.

A set of rules that governs how data is exchanged between devices on a network, covering message format, timing and the actions to take on errors.

A unique numeric address given to each device on a network so that data packets can be routed to it; IPv4 addresses are written as four dotted decimal numbers.

Hypertext Transfer Protocol defines how web browsers request pages from web servers and how servers return them; it is the basis of data exchange on the World Wide Web.

Database Management System, software that stores, retrieves and controls access to data in a database, letting users define, manipulate and protect data without handling files directly.

A column or combination of columns whose values uniquely identify each row in a table and cannot be null; it enforces entity integrity.

Structured Query Language, the standard language for defining, querying and updating relational databases, using statements such as SELECT, INSERT, UPDATE and DELETE.

A markup instruction written between angle brackets, such as

or , that tells a browser how to structure or display part of a web page.

A name-value pair written inside an HTML start tag, such as src="pic.jpg", that supplies extra information or settings for that element.