Some bee houses only have cavity sizes suitable for a single genus of bee, so they may specify that they are "mason bee houses" or "leafcutter bee houses" (though these don't cleanly equate to bee genera). And while some people call these types of things bee houses, we think ours are so nice they deserve to be called homes. As far as the other names go, they all pretty much mean the same thing, though you could make a case for insect hotels that try to support all sorts of other insects as being a distinct category.