yes
No.
The same way your next door neighbor can play a PS3 and you have the Xbox 360. You both must have your own consoles and monitors. That they are hooked up to the internet in the same room, house, city, or country makes no difference, except maybe in access to the internet.
4 at max
No, only two.
They are the same but on Xbox Live games, you can go on Xbox Live (online) and play against other people from around the world. Xbox Games that do not have Live you cannot. But it is no big worry =]
To go online with fable 3 you have to have xbox live, then push start and walk over to the multiplayer room. There you will have you settings for inivting people to jion you world, or to see other people as orbs.
No they do not
On xbox 360 yes.
Call of Duty 3 first of all needs to have the ability for online multiplayer gaming, (which it does). It also has to be able to handle multiple people on the same xbox 360 console and at the same time being able to play online multiplayer. Halo 2 for example can have 4 people playing on the same xbox console and at the same time connecting to other xbox consoles for online multiplayer gaming. If the game can do this, you must also have 2 different xbox live accounts. You can not use a guest off of another account as an xbox live account because the guests do not have the ability to talk through a mic, even if you have 2 mics. If you have 2 xbox live accounts, then the two of you on the same console can talk to other players on xbox live as long as you both have separate accounts, controllers, and mics.
The xbox 360 is made for to play with other people online
Talking to people online