Concept / Term · Foundational

Open Source

Publicly licensed code

What does Open Source mean?

Software published under a licence that lets anyone use, change and share the code. Licences vary and some carry obligations, so terms still need checking before commercial use.

Category: Writing Code: Tools, Languages & Building Blocks
Maturity: Foundational
Last reviewed: 2026-08-30

Keep exploring

IDEAn all-in-one app for writing, running and debugging code, such as IntelliJ or Visual Studio. Lighter-weight code editors like VS Code now do much the same job, and most have AI coding assistants built in.
CLIControlling software by typing text commands rather than clicking, very common in development.
SDKA ready-made toolkit of code and documentation for building on a particular platform or service.
APIA defined way for two pieces of software to talk to each other and exchange data.
LibraryA collection of pre-written code you drop into your project so you do not have to build everything from scratch. React is a well-known example.
FrameworkA structured base of pre-built code that shapes how an app is built, such as Next.js, Angular or Django. Unlike a library, a framework sets the overall structure your code fits into.
DependencyAn external library or package that your software needs in order to work.
Package ManagerA tool that installs and keeps track of the libraries a project depends on: npm, pnpm or bun for JavaScript, pip or uv for Python.

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