[Urbane Guerrilla]

A widely accepted definition is that it is violence directed at the general population to effect a sociopolitical change.

One thing the terrorists never manage to figure out is that it's a method that never wins, particularly if the targeted population is motivated to resist. That is why the Palestinian blood feud with the Israelis will never make progress: the Israelis are even tougher, and better motivated, than they are.

See also Mike German's Thinking Like A Terrorist for some illuminating study. Terrorist movements and groups are all remarkably similar in their fundamentals.