Comment by jopicornell

Not comment OP, but checkout has two very different uses merged into one: restoring files and switching branches. To not break compatibility, git has now switch and restore commands that make commands more readable and understandable.

You should avoid reset --hard because it will delete all your uncommited, and you could end up in situations where that's really bad. Using reset --keep will keep uncommited changes, and failing if any uncommited change cannot be kept.