Whats the difference between a dub mix and a remix?

to me, dub's = less or no vocals??
remix, can is just a remix?

Back when I listened to 2step music (which I still do, but not as much) I noticed that dub-mixes usually had one short sample of a vocal (or a part of a vocal)which was eddited and used through the song. I'm not sure if this is typical for dub-mixes.