Key Concepts

Commit

Whenever you save your changes in one or more files, you can create a new commit in Git. A commit is like a snapshot of your entire repository at that point in time, not just of one or two files.

Commit Message

Every time you make a commit, you need to supply a message that describes why the change was made. That commit message is invaluable when trying to understand later why a certain change was implemented.

Stage

Staging means that you have pending updates that git is aware of, but the changes have not been made permanent in the local repository.

Branch

A branch is an independent series of commits off to one side that you can use to try out an experiment or create a new feature.

Master Branch

Whenever you create a new Git project, there is a default branch created called Master. This is the branch that your work should end up on eventually, once it’s ready to push to production.

Merge

A merge is a way to take completed work from one branch and incorporate it into another branch.

Tag

A tag is a reference to a specific historic commit. Tags are most often used to document production releases so you know exactly which versions of the code went into production and when.

Pull Request

Originally, a pull request was used to request that someone else review the work you’d completed on a branch and then merge it into Master. Now, pull requests are often used earlier in the process to start a discussion about a possible feature.

Clone

Often you’ll want to download a copy of a project from GitHub so you can work on it locally.

Fork

Sometimes you don’t have the necessary permission to make changes directly to a project. If you want to submit changes to such a project, first you need to make a copy of the project under your user account on GitHub. That process is called forking the repository. You can then clone it, make changes, and submit them back to the original project using a pull request.