Command Promt is the administrative command center for a computer. it can control the computer and produce commands that can change/effect your computer, and rarely somebody else's.

People think Cmd is a huge hacking thing, but it is not. it can do no serious damage. it can not Dos somebody or hit somebody offline. so no you can't really hack with it.

Ipconfig
Tracert
Ping
changepassword
ping -l -t (#)
Nothing more you can really do with it. Accept see information on administrators and local ip's.