Acronyms:
360: Xbox 360, video game system made by Microsoft
AOE: Area of Effect, anything that causes damage or effects people within a certain radius is said to have AOE
BO: Black Ops, video game in the COD series
COD: Call of Duty, video game series
FPS: First person shooter, a video game style where you control a character and see through his/her eyes.
KO: Knock Out, usually in fighters where on character causes the other to no longer be able to fight. In Brink you can be KO'd but not dead yet.
PC: Personal Computer, probably what you're on right now
PS3: Playstation 3, video game system made by Sony
SD: Splash Damage, video game company developing Brink
TF2: Team Fortress 2, a FPS with class based warfare
I know this is a small list but I hope others will help