Programming Glossary

Short, beginner-friendly definitions for terms used throughout the lessons on this site.

A B C D E F I L M O P R S T V

A

Algorithm: A step-by-step method for solving a specific problem, independent of any particular programming language.
API: Application Programming Interface — a defined way for one piece of software to request data or actions from another.
Array: An ordered collection of values, accessed by numbered position (usually starting at 0).

B

Boolean: A value that is either true or false, used to make decisions in code.

C

Class: A blueprint for creating objects that share the same structure and behavior.
Compiler: A program that translates source code into a separate, runnable program ahead of time, before it's executed.
Condition: An expression that evaluates to true or false, used to decide which block of code runs.

D

Database: A system for storing data so it survives after a program stops, and can be reliably searched and updated.
Debugging: The process of finding out why a program isn't behaving as expected, and fixing it.
Dependency: An external package or library that a project relies on to work.

E

Exception: An error that occurs while a program is running, which can be caught and handled instead of crashing the program.

F

Framework: A pre-built structure that provides common functionality, on top of which you build an application following its conventions.
Function: A reusable, named block of code that performs a specific task, written once and called as many times as needed.

I

Integer: A whole number, with no decimal point, such as 42 or -7.
Interpreter: A program that reads and runs source code directly, line by line, without a separate compile step.

L

Library: A collection of pre-written code you can call from your own program, without controlling how your program is structured.
Loop: A block of code that repeats, either a fixed number of times or until a condition is no longer true.

M

Method: A function that belongs to a class and operates on a specific object's data.
Module: A single file of reusable code that can be imported into another file.

O

Object: A specific instance created from a class, with its own data but the behavior defined by that class.

P

Package: A collection of code (often modules) published together and installable with a package manager.
Process: A fully separate running instance of a program, with its own memory, isolated from other processes.

R

Repository: A project's codebase tracked by a version control system, including its full history of changes.
Runtime: The environment a program executes in while it's running, or the period of time during which it is running.

S

String: A value representing text, typically written inside quotes.

T

Thread: A separate line of execution within a program, running alongside other threads and sharing the same memory.

V

Variable: A named place to store a value so a program can use or change it later.
Version Control: A system that records every change to a project's code over time, so you can review or revert to any earlier point.