They are zoas (colonial sea anemones). Palythoas, protopalythoas, parazoanthus, protopalythoas and zoanthus are zoanthids and there are a few more though they rarely make it into the pet trade. Darth Mauls are palythoas.
An easy way to tell, though not 100% accurate, is that palythoas and protopalythoas will close up over foodstuffs, whereas zoatnus are filter feeders and will not close over feeds unless it is from irritation of the food particles.
Protopalythoas slime when touched and palythoas do not. Sand embedded into the tissues of wild colonies also is a way to tell the difference, but with the increase in tank raised zoanthids, this is not a reliable way to differentiate between the different types ina ll cases.