1.3 History and HEAD

Git history is not a pile of random backups. Commits form a chain, and each commit knows its parent commit.

Inspect history

git log --oneline

git log shows history starting from the current commit. --oneline compresses each commit into one line, which is easier to scan.

What is HEAD?

HEAD is the marker for your current position. Usually, HEAD follows the current branch: when you make a new commit, the branch moves forward and HEAD follows it.

If you check out an old commit, HEAD moves to that old position. It is like standing at a past moment in history.

Commit messages are for future readers

A commit message is not decoration. Weeks later, Fix login redirect after OAuth callback is much more useful than fix.

git commit -m "Add empty state for search"

A practical habit is to start with a verb: Add, Fix, Update, Remove, Refactor.