how to back to a commit git code example

Example 1: git go back to previous commit

git checkout 12feg3435 #commit ID

Example 2: 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