The command line is offered by a program called your 'shell'. Your shell by default is called 'bash', the Bourne Again Shell. Bash could be replaced by another program if you wanted. Cannot move a directory across between filesystems.
None Deletes an entire subtree.
Can be slow on big subtrees. None Change current dir to home dir. None Change current dir to given dir. None Change permissions for a whole subtree. You must be root to use this command.