It's your account on the Xbox network that shares your gaming history and gamerscore with other players. If you want you can add a mini bio about yourself. It also alllows you to select your gaming prefrence or style. Mine is recreational, meaning I play in my downtime. I can't recall the other prefrences. There are different deals for your membership; gold memberships allow you to access all the goodies on live. You can watch movies on your Netflix account, check your facebook and twitter, join parties with your friends, etc. Hope this helped.