Unity interface is the default interface in Ubuntu 11.04 Natty Narwhal. It consists of the dock and launchers. However, if you don’t like the dock, animations and the interface as a whole, you can just disable it and login to Ubuntu Classic Desktop.
Logout and type in(or select) your username and in the bottom panel, select “Ubuntu Classic Desktop” instead of “Ubuntu Desktop Edition”. When you login next time, the same will be selected by default.
To re-enable Unity interface, just select “Ubuntu Desktop Edition” during login.