Please note that this does more then what the parent suggests doing by "git checkout". This destroys untracked changes and resets your current branch-pointer t

Please note that this does more then what the parent suggests doing by "git checkout". This destroys untracked changes and resets your current branch-pointer to <commit>, removing all the commit-history that comes after <commit>. (You can still recover them from the database, e.g. with "git reflog")