Newb and noob may have somewhat different connotations. Newbs are simply newcomers—noob and n00b, on the other hand, generally mean someone who is obnoxious, annoying, or breaks the rules or cannot play effectively; whether they are actual newcomers or not is mostly irrelevant.
Therefore, a noob may be someone who has been around for a long time but still engages in behavior that he or she should have learned is unacceptable. Noobs are generally confident in what they are doing, but in reality are annoying others. "Newb" is not necessarily an insulting word, but "noob" usually is.
If someone makes an unintelligent comment on a forum or asks a question that even other newbies could answer then it is said that they are making a "noobish" comment or asking a "noobish" question. However, due to the evolution of language, the term noob or 'n00b' is now used both ways and newb is used only infrequently.
More experienced players are often encouraged to give friendly advice and help to newbs, to support them as they tackle the learning curve of whichever game they're playing, and some game servers are set up explicitly for the purpose of allowing newbs to gain experience before entering more competitive environments.
"Noob" can also mean a person who claims to know a lot about a subject but in truth does not. It was first used in hacker groups on the BBS chat systems in the 1980s. It is important to note that noob and newb are not necessarily interchangeable. Many times the term noob or n00b will be used by veterans to degrade a user for their lack of knowledge, or claims to know more than they truly do.
Recently, the spelling noob has been used more interchangeably with "newb", however, and is being used in a more joking manner, usually among friends and users on good terms when one user makes a mistake that most veterans would know better not to do, whereas a "newb" or "noob" wouldn't know better.
For example, in the computer sense, a user on a bulletin board may call a veteran user as a noob in a joking manner because they didn't search for a topic currently open with the same discussion before posting a discussion of their own.
In online gaming, the term is also often used as a general insult. Frustrated players on the losing team may refer to the winning team as noobs. In this case there is no actual connotation of newness meant; the word is simply being used as an insult. By the same token, members of a dominating team may use the term "noobs" (n00bs) to further frustrate their opposition by implying a general lack of skill on the losing team's part, such as camping (staying in the general vicinity, usually a spawn point, for an extended period of time, especially America's Army and DOOM) or wastefully firing at a wall, wasting ammunition and time, and alerting the enemy. Veteran players might also use Noob to criticize cheap tactics or overusage of unbalanced weaponry.
In an online team game where friendly fire is turned off, a noob "tactic" would be to overuse explosives in cramped areas around fellow teammates. Noob usually applies in games where team-play is important, and the players choose to completely ignore the team structure and goals. Experienced players who find themselves on the losing team may claim to all players that they are on the 'noob team' in order to retain their experienced status and pass off the loss as solely the fault of their teammates. Some other "noobs" are players who overly use "uber weapons" to defeat other players, players who "kill-steal" from others, and players who scam others into losing their items or money.
"Noob" has frequently been written in different forms. Because of the proximity of the "j" key to the "n" key, players in online games often typed "j00b" or "joob" by accident, and the recent proliferation of "nub" has often turned into "jub". Though neither "joob" nor "jub" have any meaning, their connection with "noob" makes the two words equivalent. "B00b" and "m00b" sometimes appear in a similar manner ("b" and "m" are right beside "n" in a standard computer keyboard). This is quite similar to the origin of the internet terminology "pwned". According to a popular theory on the origins of "pwned", it originated from owned when an anonymous gamer made a typing error by pressing the "p" key which is located to the right of the "o" key on a standard computer keyboard.
The term "Noob" can also have variants, such as "Hecknoob" in the MMORPG Anarchy Online where a type of monsters known as "Hecklers" are routinely killed as an easy source of experience and levels. Some players will level exclusively on these monsters, neglecting other forms of leveling and thus becoming inexperienced in gameplay. Other variations of the term are the "Noob Cannons" and "Noob Suits" of Planetside, referring to the rocket launchers and MAX suits that underexperienced players use to gain easy or dishonorable kills