Titan is more of a offensive, front line type of class. Hunter are like a scout, marksman class. The warlock is a Mage, support class. All classes can use all weapons and each have a specific special ability and they have a unique armor type for example: Titan is heavy armor, hunter like a medium armor, and warlock light armor. Also, I believe each class have a specific grenade type not completely sure. Hope this helps with your decision.