Branches

A branch is a name for a line of work. Under the hood it's tiny: a label that points at one commit. Here, every new repository starts on a branch called main, today's usual name for the first branch. On your own computer git may still call it master, as Basics › A new repository explains.

HEAD tells git which branch you're on. When you commit, the branch you're on moves forward to the new commit, and every other branch stays where it was. That's what lets you try something on one branch while main stays untouched.

Command	What it does
git branch	Lists the branches. A * marks the one you're on.
git branch <name>	Creates a branch on the commit you're on. You stay where you are.
git switch <name>	Switches to a branch: HEAD moves to it, and your files change to match its commit.
git switch -c <name>	Creates a branch and switches to it, in one step.
git branch -m <old> <new>	Renames a branch. With one name, it renames the branch you're on.
git branch -d <name>	Deletes a branch, but only if its commits are already in the branch you're on.
git branch -D <name>	Deletes a branch even if its commits are on no other branch.

Creating, renaming or deleting a branch never changes a commit. Only the labels move, and the Live Graph shows them moving.

Git won't delete the branch you're on: switch to another one first. And -D really does throw away the label. A commit that was only on that branch is then on no branch at all, and the Live Graph shows it faded.

Switching with uncommitted changes

Changes you haven't committed yet don't belong to any branch: they're just in your files. When you switch, they come along. git switch -c <name> always takes them with you, because the new branch starts on the commit you're on. So if you started some work on main that belongs on its own branch, make the branch, then commit there: main stays as it was.

Switching to an existing branch takes them along too, unless that branch has a different version of a file you changed. Then git refuses to switch rather than overwrite your work, and tells you which files are in the way: commit them first.