Ballroom dancing can get a little complicated in that there are two different styles of dancing, two different categories of dancing within each style and four to five different dances per category. Let's first start with a list showing the differences between each style:
Within the American style you can dance either "rhythm" or "smooth" dances:
Rhythm dances include:
Smooth dances include:
If you are a competitor of the American style and you compete in both the rhythm category and the smooth category, it is said that you compete 9-dance (five rhythm dances + four smooth dances = 9 dances).
Within the International style you can dance either "Latin" or "standard" dances:
Latin dances include:
Standard dances include:
If you are a competitor of the International style and you compete in both the Latin category and the standard category, it is said that you compete 10-dance (five Latin dances + five standard dances = 10 dances).
American vs. International Styles
A big difference between the styles is that the American style of dancing is competed and taught predominately in the United States whereas the International style is competed and taught all over the world. The American style of dancing was also derived from the International style and is often considered more simple and easy to learn which is why most dance studios teach it instead of the International style. The American style of dancing is considered more of a social style of dancing and is the style that most people will be dancing at your local venue.
American Rhythm vs. International Latin
American rhythm and International Latin are similar in that they both share a rumba and a cha cha dance and rhythm's swing is a slowed-down version of Latin's jive. The Latin style tends to be more structured and based on technical ability and sharp, crisp lines. Though Latin incorporates precise hip movements it is more focused on a snappy leg action created by stepping onto a straight leg instead of a bent leg. Rhythm dancing focuses more on creating hip movements and therefore the straight leg action is less of a priority. To increase hip movement, many rhythm dancers and instructors will advise you to step onto a bent leg instead of a straight leg like in the Latin style of dancing.
American Smooth vs. International Standard
Smooth and standard share all of the same dances except for the quickstep which is exclusive to the International style. The biggest difference between smooth and standard is that in smooth you are allowed to do "open" moves, meaning that the partners can break away from each other and do spins, dips or side-by-side movements. In standard dancing the partners are always connected in hand hold and with lower body contact. Like International Latin, International standard is also more technical and American smooth is more social and less restricted in steps and movements.
Should I dance American or International?
A good rule of thumb is if you intend to only dance socially, learn the American style. 99.9% of social dancers will be dancing the American style at any given venue in the U.S. If you want to compete only in the United States, American is also a good choice. If, however, you want to compete all over the world (or just compete in general) or you intend to move to Europe, it's highly suggested that you learn the International style. If you are familiar with ballet and modern dancing, here's an analogy: the International style is like ballet. It's very technical and will make you into a very efficient and precise dancer. The American style is like modern dancing. Technique is still involved but it isn't as focused on it as the International style but it still looks good and is a lot of fun.
Looking for more information? Here's a really great site to get you started.