How to use restart command in Ubuntu 12.10 terminal

My PC is an emachine (eME732) running Ubuntu 12.10 32-bit operating system. I tried using the restart command at the root prompt, but got the following output
                                                 restart: missing job name

Kindly advise what the job name should be. I ran the command restart --help. This advised the following
                                                Usage: restart [OPTION]... JOB [KEY=VALUE]...
                                                Restart job.

I'm new to running CLI commands in the terminal and would be most grateful for help and advice on learing to use this, please.

Thank you for your kind help.