History

In a nutshell, history allows you to see a git repository like a collection of commits and references

Which commit is a new one linked to?

The answer is "the commit pointed to by HEAD"

The special tag HEAD

HEAD is a special reference, pointing to the last commit of the current working branch
in an ordinary situation

Which operations move HEAD?

• Changing branch (switch)
  move HEAD to the last commit of another branch
• Creating a commit (commit)
  move HEAD to the new commit

What if we want to move HEAD
to a specific commit?

To do this we can use the checkout command with the hash of the commit we want move HEAD to

git checkout <commit_hash>