cpanel is control panel. did this word mean something for you? cpanes is area/page that we can controlling our stuff (it will different according what kind of cpanel that you have). i mean if this about domain then your cpanel is where u can control/administrate your domain(s)
cpanel is ur webhosting control panel. you can add e-mail is, ftp accounts, databases, & a lot of things for your website using cpanel.