Une métaphore amusante consiste à considérer Git comme un utilitaire de gestion des chronologies.

Where am I ? Bash hint !

parse_git_branch() {
     git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}
export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ "

Useful links

​https://git-scm.com/docs/git-commit
​https://www.atlassian.com/fr/git/tutorials/undoing-changes

Useful commands

git-checkout

git checkout MY_BRANCH - Switch branches or 
git checkout old_commited_files.F90 restore working tree files
https://git-scm.com/docs/git-checkout

git-restore

git restore deleted_file.F90 Restore working tree files
git restore --source MY_BRANCH~2 file_before_last_2_commit.F90