Glossary

Your copy is ahead when you have snapshots that origin doesn't have yet.

Your copy is behind when origin has snapshots you haven't pulled yet.

A parallel line of history where you try an idea without touching the main version.

Download a full copy of a repository, including its whole history.

A saved snapshot of your changes, with a short note that describes them.

Two people changed the same line, and Git needs you to choose which version stays.

Put a file back the way it was in your last snapshot.

A copy of someone else's repository under your GitHub account, so you can change it freely.

The ordered list of every snapshot in a repository. Git also calls it the log.

Tell Git to never track a file, like private notes or passwords.

The branch most projects treat as the official version.

Bring the changes from one branch into another.

The usual name for the copy of your repository on GitHub that everyone works from.

Bring new snapshots from origin into your own copy.

On GitHub, a proposal to merge your branch so others review it first.

Upload your new snapshots to origin so others see them.

A tagged version you publish on GitHub so others download that exact copy.

A folder of files whose history Git keeps track of.

Make a new snapshot that reverses an earlier one and leaves the old one in history.

Someone reads your pull request, leaves comments, and approves it before it merges.

Put a changed file in the staging area so the next commit includes it.

Where you collect the changes that go into your next commit.

Change which branch you work on. Your files change to match it.

A label on one snapshot, like Summer edition, so you find it again later.

Move a file out of the staging area. Your edits stay in the file.