There are many different kinds of chests, from simple boxes to ornately decorated varieties, but they all function about the same.
Some chests are spawned as locked chests, but only appeared in a single level-only quest is an Ogden's Sign. They can be only opened with after talking to oh-so naughty Snotspill. Each time you open a locked chest, you get a Tavern Sign for Ogden to return for a reward. Rogues are expert lock-pickers and she requires a Trap Disarm to open locked chests.