What are the Character dances?
The Irish Jig and the Sailors Hornpipe are usually grouped in with the nationals (as far as I know), but I like to refer to them as character dances because you have to do a bit of acting and adopt a character when you dance them. In the Irish Jig, the dancer pretends to be an angry Irish Washerwoman whose laundry has been trampled by naughty children. She shakes her fists at them, flounces her skirt, stamps her feet, etc. In the hornpipe, dancers pretend to be sailors, and mimic movements the sailors do on a ship. Here is a bit more info on several dances.