Online it originally meant the act of posting a message in a newsgroup (and later on a blog) that is obviously exaggerating something on a particular topic, hoping to trick a newbie into posting a follow-up article that points out the mistake.
In general, to "troll" means to allure, to fish, to entice or to bait. Internet trolls are people who fish for other people's confidence and, once found, exploit it. Trolls vary in nature; here are four types of online trolls:
Playtime Trolls: an individual plays a simple, short game. Such trolls are relatively easy to spot because their attack or provocation is fairly blatant, and the persona is fairly two-dimensional.
Tactical Trolls: This is where the troller takes the game more seriously, creates a credible persona to gain confidence of others, and provokes strife in a subtle and invidious way.
Strategic Trolls: A very serious form of game, involving the production of an overall strategy that can take months or years to develop. It can also involve a number of people acting together in order to invade a list.
Domination Trolls: This is where the trollers' strategy extends to the creation and running of apparently bona-fide mailing lists.
You have probably heard various opinions about how to deal with people
who write insulting or provocative remarks on various Internet forums. The most common is "Don't Feed the Trolls",
which says that all the people in the forum should avoid responding to