The software world
GitHub
The most widely used website for hosting git repositories. It holds the shared copy of a project that a team pushes to and pulls from, and adds the collaboration layer around it — pull requests, code review, issues, and automated checks.
Why it matters
Part of Version control (git) → It's the difference between git as personal undo and git as teamwork. Git itself is happy to run entirely on your laptop; GitHub is where the copy everyone agrees is the project lives. It's also why main matters — GitHub is showing everyone the same trunk. (GitLab and Bitbucket do the same job.)
see also