The most obvious difference between American style and international style in the smooth/standard dances is that you can separate from your partner in American style, but not in international style. Any time you see a couple doing underarm turns in waltz or the big, open fan moves in tango or anything like that, it's American style. International standard stays in closed positions (OP, PP, etc. included) throughout. Some of the figures are going to be different, too, but the general technique is the same. If you do some web searching, Google's a good starting point, you should be able to find more details about the differences between American and International. This is the most obvious one though. Which one you choose to do is up to you. Some people prefer one, others like the other better. It's personal preference, do what you like.

--
James Marshall
marshall@astro.umd.edu http://www.astro.umd.edu/~marshall