To rage quit means to quit a game before the match is done. Mostly seen/heard of in first-person shooter games. People who rage quit are those people who play legitimately and can no longer take being killed by a lag switcher, camper or nolifer (one who does NOTHING else but play video games). Rage quitting also saves you from possibly throwing your controller and breaking it or yelling at the top of your lungs. Rage quitting is always the better option, especially if you're losing, because if you rage quit a match before it's over, you get a loss on your record. So rage quitting in a match that you know you're going to lose isn't necessarily a bad idea.
Nolifer: *kills the rage quitter 10 times before he can even kill anyone*
Rage quitter: GOD DAMN IT! FUCK THIS! THAT GUY IS MUST HAVE NO LIFE WHATSOEVER AND DOES NOTHING ELSE BUT PLAY THIS GAME! I'M OUTTA HERE!