Detached HEAD
In plain terms
A Git state where you're on a commit, not a branch.
Going deeper
Detached HEAD means your working state points directly at a commit rather than a branch, so new commits aren't on any branch. Edits there can be lost if unsaved.
Under the hood
Useful for inspecting old states; create a branch to keep any new commits made there.
Examples
Checking out old commits, git checkout <hash>, inspecting history.
Think of it like...
Like standing on a specific page with no bookmark, your notes there may get lost.