Terminal (or Terminal.app) is the program included in Mac OS X for running applications and issuing commands using the command line interface. These programs are controlled by typing lines of text, rather than using the mouse or keyboard commands in the usual graphical user interface (GUI).
I've recently bought a usb-ethernet adapter (not apple) and I get internet connection. In my university we have to put a specific mac address but I can not change it. I have tried with sudo ...