What are the martial arts?
Before you head into a martial-arts school (or dojo) you're probably going to ask yourself, "Am I going to have to throw someone over my head? Break concrete? Use a weapon?" First, all martial arts use variations of the same movements, such as kicks, punches, strikes and throws. However, some are considered "hard" (based on attack), while others are considered "soft" (focused on blocking and defensive moves). Here are some specifics.
Aikido 100-percent soft style. No formal kicking or punching training; instead, you use the energy of your opponent to turn an attack into a submission, using shields, rolls and throws.
Karate 50-percent hard/50-percent soft style. Karate was designed as a swift and aggressive means of self-defense, using blocking and strikes, but very little kicking. There is a wide variation in how it is taught, so you should ask the teacher (or "sensei") about whether there is sparring in his or her class.
Tae Kwon 75-percent hard/25-percent soft style. Uses both kicks and strikes; most classes practice balance exercises, and some throws.