how to undo a specific commit in git code example

Example 1: git how to roll back to a commit

//git use a new commit to replace an old commit,commit moves foward not backward
git revert <commit hash>
//Git goes back one spot on the log,undone this commit and go backward one commit:
git reset HEAD~1
//Git looks for and rolls back to a certain file:
git checkout commit-hash-here -- file/location/and/name

Example 2: how to go to a previous commit state

# This will detach your HEAD, that is, leave you with no branch checked out:
git checkout 0d1d7fc32