Razz is a variation of poker similar to the "Lo" portion of Stud Hi-Lo. It's played in a similar manner to Stud except there is no high hand. The player with the low hand wins the whole pot. The low hand qualifiers in Stud Hi-Lo do not exist in Razz so your hand can contain paired cards and cards above 8 in rank. Aces are low and flushes and straights are not a factor in Razz either but paired cards will count against you, though. For example, 9TJQK is a better (lower) hand than 22345 because five unpaired cards always beats a hand containing a pair. So when choosing the best five cards from the group of seven, the ones that would make a pair (or trips or quads) will be eliminated first, even if their ranks are lower than the remaining fives cards. Of course, the software does this automatically, the players do not have to manually pick their lowest 5-card hand.
The only other difference from Stud is that the player with the worst (highest) 3rd Street card has the Bring-in (king of spades is highest, ace of clubs is lowest) and the player with the best (lowest) hand showing is first to act on the remaining rounds.