Whereas stroke play scoring is based on the total number of shots for the entire round, in match-play, you win, tie or lose each hole until you run out of holes and a winner is declared… unless of course it ends up in a tie.
If you par the first hole, for example, and your opponent bogies it, you’re “one-up”. Beat him/her again on hole #2 and you’re “two-up”. If, for example, you are “three-up” but there are only two holes left to play, you win the match!
In match play, if Player A is a 10 handicap and Player B is a 19 handicap Player A would play as “scratch” (zero handicap) and Player B would get one stroke off his score on the nine hardest holes. In other words, the 10 handicap becomes zero and the 19 handicap becomes nine.