ssh doesn't have commands, as such. And Terminal doesn't use ssh. What you have is a shell prompt. You can do things like ls, cd, cp, mv.. Unixy stuff.
If you want 'cool' stuff, install Erica's (iPhone) Utils and play around in /var/root/bin/
Not strictly true. top shows as many processes as it can fit on the screen, with a variety of sorting options. If you wanted to view all processes you'd use something like: