Rogues abilities are used in order to both deal damage and attempt to avoid it.
The majority of rogue abilities fall into one of three categories:
Opening moves - Openers are what every rogue should begin a fight with. These powerful attacks are only usable while Stealthed and break the Stealth effect upon use. A common tactic for burst damage is to open on the enemy, Vanish, and open again. A few examples are Ambush, Cheap Shot, and Garrote.
Combo moves - These moves are the bread and butter of a rogue. Combo moves generate Combo points, which are required to use a finishing move. They deal the majority of your damage and fill the void between your openers and your finishers. A few examples are Sinister Strike, Mutilate, and Hemorrhage.
Finishing moves - These are the rogue's strongest attacks. They require Combo points to use and increase in effect depending upon the number of Combo points you have on the target. A good rogue will need to learn to use the right finishers at the right time, as there are a lot of them. A few examples are Eviscerate, Envenom, and Rupture.