It has a number of different specific variations, though the most commonly recognized is probably five-card stud. Whatever the case, we know now that stud poker has taken on a pretty commonly understood format in poker rooms all over the world. Actually, according to one report from the Southeast Missourian back in the early-'90s, one official said of stud horse poker, 'nobody knows what it is.' So hey, maybe that previous description wasn't far off. I was making sure you were paying attention. The term 'stud poker' actually originated as 'stud horse poker,' which involved painting 52 horses with the 52 official card values and riding them to different spots around a giant field to signify dealing out cards.
The way we look at it, the 'stud' may as well be silent it's just a more official term for poker, right? Pretty much everyone who's ever visited a casino or looked into playing cards has heard the term 'stud poker,' and most probably haven't ever wondered where it came from.