What Is Version Control?

Version control is a system that tracks every change made to a project's files over time, who made each change, and why. Instead of ending up with files named report-final.docx, report-final-v2.docx, and report-final-REALLY-final.docx, version control keeps one set of files with a complete, searchable history behind it — and Git is by far the most widely used version control system in the world.

In Git, a project tracked this way is called a repository (or "repo" for short) — just a folder that Git is watching. Each saved snapshot of the project is called a commit, and every commit has a short message describing what changed. Over time, this builds a full timeline you can look back through, compare, or even travel back to if something breaks.

A Git "commit" is a saved snapshot of the project at a specific point in time, along with a message describing the change.

Why does this matter so much? Three big reasons: you can always undo a mistake by going back to an earlier commit; you can see exactly what changed and when, which is invaluable when something breaks and you need to find out why; and it lets multiple people work on the same project at once without overwriting each other's work — which is the subject of the next level, GitHub.

What is a Git "repository"?