A slang that used to stand for "Laugh out loud" but now frequently represents slight humor and acknowledgement of what is said. If someone was seriously laughing, instead of lol they would type LMAO or LMFAO! Lol is just another way to bump the conversation.
Someone: omfg, my dad took my car away from me!
someone2: lol... yea now we can't go to wal-mart.
When one installs a game which they have pirated
Person 1: Yo Dawg, I instealled Call of Duty Modern Warfare 3 because it is so expensive.
Person 2: Yes, I insteall all my games. Paying for games is what nubs do.