The way in which you carry yourself. Swag is made up of your overall confidence, style, and demeanor. Swag can also be expanded to be the reputation of your overall swagger. You gain swag, or "Swag up", by performing swag worthy actions that improve this perception. A person can also "swag down," by being an overall pussy and garnering negative swag for their actions. Swag is a subtle thing that many strive to gain but few actually attain. It is reserved for the most swagalicious of people. Swag can also be quantified, with point systems existing in some circles of friends.
"I got with two girls last night"
"Awesome dude, that's some swag"
"I think one of them was my sister though..."
"I'm digging that strut son, I like your swag"
"I don't think I can go out tonight, I got too much work"
"Swag up you little bitch"
"If I finish this pizza in under 3 minutes, can I get a swag point?"
"You really don't understand swag...do you?"