A newb is a particular person who is bad at gaming. It doesn't have to be on games, it can be on the internet. Remember, a newb is not the same as a noob or n00b. A newb tries to get better and tries to turn into a pro, meanwhile a noob or n00b tries to beg and plead for modship, extras, etc., they also try to play the game without any help and tries to think they're doing the right thing.
(tip: these words are not meant to be insults.)
"Newb: How do you get the c4?
Battlefield player: You must be a newb, you get it by trying to level up.
Newb: Thanks for the tip. :)"
(THIS IS AN EXAMPLE OF A NOOB OR N00B:)
"Noob: *shoots down an friendly helicopter* Cool! I got points! Hey admin, can I get more good guns?!
The guy in the helicopter: Hey noob! Stop killing me! I'm just trying to unlock some shit for my helicopter!"