X-box Live
X-box live is a place where you can play games with friends online without them coming to your house. You can have friends, and people you hate. You use a gamertag that you make and tell one of your friends that has live it then they can friend you and you can play together. In halo you use matchmaking to play with other people in huge or small games. It is very fun and can get you lots of credits when you play the arena(on super jackpot weekends).