panel 1:

have you ever seen refs/heads/main or HEAD and wondered what they mean?

here’s the deal:

• head = branch
• HEAD = current branch

(yes, these are TERRIBLE names)

panel 2: a head in git is a branch

nobody really uses the term “head” for a branch except the official git docs though

panel 3: HEAD is the current branch

for example HEAD could be set to main

it’s stored in .git/HEAD

Unless you don’t have a current branch…

panel 4: HEAD can be a commit ID instead of a branch

This means you have no current branch. Git calls this a “detached head state” (another terrible name!)

(silly picture of a stick figure whose head has fallen off)

fixing this is easy though:

git checkout BRANCHNAME

panel 5: the current branch matters for these commands

git commit
git rebase
git merge
git cherry-pick

these 4 will work if you have no current branch but will create commits that you have no easy way to refer to

git pull
git push

these don’t work at all if you’re not a branch