The following is a passage from Wikipedia on starting hands probability:
The 1,326 starting hands can be reduced for purposes of determining the probability of starting hands for Hold 'em—since suits have no relative value in poker, many of these hands are identical in value before the flop. The only factors determining the strength of a starting hand are the ranks of the cards and whether the cards share the same suit. Of the 1,326 combinations, there are 169 distinct starting hands grouped into three shapes: 13 pocket pairs (paired hole cards), 13 × 12 ÷ 2 = 78 suited hands and 78 unsuited hands; 13 + 78 + 78 = 169. The relative probability of being dealt a hand of each given shape is different. The following shows the probabilities and odds of being dealt each type of starting hand.
The equation used to calculate the total possible number of starting suited hands and unsuited hands is 13 x 12 ÷ 2, but what I don't get and try to figure out is what does 12 and 2 represent in the equation?
Another thing I'm confused about is how the suit combinations for each unsuited non-paired hand is calculated?