You are placed in your home directory once you log in to UNIX system. Your home directory is your private area where you can create your own files and directories, and perform other tasks. You can also change to another directory for your working directory. To see what your home directory is, log in and type the command pwd at the prompt. Most UNIX commands are in lower case.
Some commands have several options or tags which modifies the way in which a command works.
Finds out who the user is. Obtains more information about users. Year must be entered in full. You must know your old password to use this command. There is a very useful document on the UNIX system that contains instruction on how to select your password and what you should avoid.