Toggle Clasp: A “bar and hoop” type clasp. They don’t accidentally open (just in case you’re worried). My bracelet has one of these, and it has never opened on its own. Toggle clasps offer a variety of styles not available from other types of clasps.
Lobster Claw Clasp: A “pinch and lock” type clasp. These are generally smaller and less noticeable than other types of clasps. They lock shut and are very secure.
Tube Clasp: A “slider” type of clasp. The small tube on one side slides into the larger tube on the other side. These are great for wider, cuff-type bracelets.