on the stern of my wireless modem here is an ethernet nouns that can plug into my computer.
Answers:
Ethernet uses a cable, is faster and more in safe hands.
Wireless uses radio top and an antenna and doesn't tie you to the router physically (so you can move around more freely).
nothing.
Ethernet is a type of introduce yourself, that runs any on physical lead (RJ45 and Cat5) or across a wireless adapter.
If you enjoy a RJ45 port on your router/switch at home, the nouns speed is typically MUCH faster than what you can receive via wireless.
100mbps wired vs. 11mbps wireless