Ways to undo changes

`git reset --soft HEAD~1`

Undo last commit, keep changes staged.

`git reset HEAD <pathname>`

Unstage changes for a specific file or files

`git checkout --<pathname>`

Discard changes in working directory.

`git reset --hard HEAD~1`

Undo last commit and discard changes.

`git revert <commit>`

Revert the changes introduced by a specific commit