Trolls

An Internet Troll is a person that posts provocative or off-topic messages on an online community (chat room, forums, etc) to purposely either cause another user to respond emotionally or to disrupt a serious, on-topic discussion. They often create multiple accounts. These users are often drawn to new users because most veteran users are used to them. New users, however, won't understand and can be easily upset or even worse.

Trolls can also refer to people who spam a lot.

Spammers
These are trolls that posts chain posts or advertise sites. The ones that post chain posts aren't always 'trying' to be rude but may simply be new to the Net and don't realize how annoying it is.

Advertisers post messages similar to " Hey if you like this video, you'll love hotanimebabes(.)com. just remove the '' and you're good to go." Even if the video had nothing to do with that.

Flag Trolls
Trolls that surf sites like YouTube or DeviantArt (sites were you can post content) and flag content for no reason. Some users believe that "some soccer mom probably flagged it." Most sites, however, won't do anything to the post unless there really is something wrong it.

General Troll
A basic troll. They will post something to make someone upset. For example, they may post a comment to a YouTube video saying "This video is s***! I hope you die tomorrow! Faggit!" Of course, if went to their page they won't have any videos posted themselves. If they do, it's crap. There is no point in replying. They will either not reply (because they just want to see that they ruined your day) or you will just be dragging it even further.

Off Topic Troll
A person that posts in a forum devoted to one subject and ruins the conversation. It's the same feeling as that guy that interjects during a conversation with a stupid comment. For instance: The forums topic is Ghosts/

user1: one halloween when I was little I saw a ghost trick or treating in a group of kids. He was transparent and just walking behind the other kids but no even noticed!

user2: wow! thats pretty creepy!

user1: I know!

user3: did it ever interact with anyone?

user1: No but it did glare at me for a few seconds.

troll: did any1 else see Avatar yesterday?

user3: ???

troll: it was cool!

user1: do u mind?

Progress Block Troll
In the world of MMORPGing, the point of the game is to complete some sort of task in order to progress. A troll will block you from completing this task and progressing. Say that you have to collect mushrooms in order to level up, the troll will come from nowhere and start taking all of them so you can't.

Anti-fan Troll
Say you join a website devoted to the love of anime and while everyone is talking about how awesome anime is, this one person says "anime sucks." These trolls want to upset a large audience so they insult the thing they know everyone there loves.