Punjab PSEB SS Computer Science key terms

A finite, ordered set of unambiguous steps that solves a problem or completes a task. Every step must be clear enough to execute, and the process must stop after a limited number of operations.

A diagram that shows the sequence of steps in a process using standard symbols: oval for start and stop, parallelogram for input or output, rectangle for processing, and diamond for decisions.

A structured, English-like description of an algorithm that follows programming logic without strict syntax rules, so it can later be translated into any programming language by a programmer.

A translator program that reads a complete source program written in a high-level language and converts it into machine code in one go, reporting all errors together before execution begins.

A translator that converts and executes a high-level program line by line, stopping at the first error it meets. It is slower than a compiler but useful for testing and learning.

A system program that converts assembly language, which uses short mnemonics such as ADD and MOV, into the binary machine code that the processor can execute directly.

The original program text written by a programmer in a high-level or assembly language, which must be translated before the computer's processor can run it.

The translated machine-level output produced by a compiler or assembler from source code. It is not yet a complete runnable program until library routines are linked with it.

A tool that joins object code files and required library routines into a single executable program, resolving references between modules so the final file can be loaded and run.

An operating system utility that copies an executable program from secondary storage into main memory and transfers control to it so that execution can begin.

A named storage location in memory whose value can change while a program runs. Its name, data type and scope determine how it is used in statements.

A value that is fixed when a program is written and cannot be altered during execution, such as the value of pi or a maximum array size declared in code.

The name given by a programmer to a variable, function, array or other program element. It must follow naming rules, such as starting with a letter and containing no spaces.

A word reserved by a programming language for a fixed purpose, such as if, while or int. It cannot be reused as a programmer-defined name because the compiler treats it specially.

A classification that tells the compiler what kind of values a variable may hold and which operations are valid on it, for example integer, floating point, character or string.

A symbol or word that performs an operation on one or more values, such as addition, comparison or logical AND. Operators are grouped by precedence to decide evaluation order.

The value, variable or expression on which an operator acts. In the statement a + b, the plus sign is the operator and a and b are the operands.

A combination of variables, constants, operators and function calls that is evaluated to produce a single value, for example (x + 5) * 2 or a > b.

A complete instruction in a program that performs an action, such as assigning a value, calling a function or controlling the flow of execution. It usually ends with a semicolon.

A construct that decides the order in which statements run: sequence for straight-line execution, selection for choosing between paths, and iteration for repeating a block of code.

A selection structure, such as if, if-else or switch, that tests a condition and executes one block of statements when the condition is true and another when it is false.

A control structure that repeats a block of statements while a condition holds or for a fixed number of times. Common forms are for, while and do-while loops.

An expression that evaluates to exactly one of two values, true or false, usually built with relational operators such as < and >= and joined with AND, OR and NOT.

A named block of code that performs a specific task, can receive arguments and may return a value. Functions make programs modular and avoid repeated code.

A variable listed in a function's definition that receives a value when the function is called. The actual value supplied by the caller is called an argument.

The result a function sends back to the point where it was called, using a return statement. A function that returns nothing is usually declared as void.

A technique in which a function calls itself with a smaller or simpler input until a base case is reached, which stops the calls and produces the final result.

The condition in a recursive function that is solved directly without another recursive call, preventing infinite recursion and allowing the pending calls to return.

A collection of elements of the same data type stored in consecutive memory locations and accessed by a single name plus an index, which usually starts at zero.

A number or key that identifies the position of an element inside an array or string. In most languages the first element has index 0, not 1.

A sequence of characters treated as one unit of data, such as a name or a sentence. Strings support operations like length, concatenation, comparison and substring extraction.

A variable that stores the memory address of another variable rather than a data value. Pointers allow indirect access to data and are used to build linked structures.

A unique number that identifies a byte location in main memory, used by the processor and by pointers to locate and access stored data.

A linear data structure that works on the last-in, first-out principle, where insertion and deletion both happen at one end called the top, as in undo operations.

A linear data structure that works on the first-in, first-out principle, where items are added at the rear and removed from the front, like a line of people.

A dynamic data structure made of nodes, each holding a data item and a pointer to the next node, so elements need not sit in consecutive memory locations.

An organised collection of related data stored so that it can be easily accessed, managed and updated, usually controlled by database management software rather than by separate files.

Database Management System: software that lets users define, store, retrieve, update and secure data in a database while handling concurrency, backup and access rights.

A column or set of columns whose value uniquely identifies each row in a table. It cannot be null and no two rows may share the same key value.

A column in one table that refers to the primary key of another table, creating a link between the tables and helping to enforce referential integrity.

Structured Query Language, the standard language for creating and querying relational databases. Its main command groups are DDL for structure and DML for data.