Self-defense (U.S. Spelling) or self defence (International) refers to actions taken by a person to prevent another person from causing harm to one's self, one's property or one's home.

Many styles of martial arts, usually Asian styles, such as Ju Jitsu, Karate, Taekwondo or Wushu are practiced for self-defense. Some styles train almost exclusively for self-defense (Wing Chun, Krav Maga), hereby putting emphasis on the bodies' weakest pressure-points [1]. Others still, are practiced for other reasons and not intended for self-defense at all (eg Tai-Chi, Tae Bo). However, some martial arts that are practiced primarily for sport, such as boxing or judo can be effectively applied for self-defense.

A good self-defense class can teach you how to size up a situation and decide what you should do. Self-defense classes can also teach special techniques for breaking an attacker's grasp and other things you can do to get away. For example, attackers usually anticipate how their victim might react — a kick to the groin or jab to the eyes, for instance. A good self-defense class can teach you ways to surprise your attacker and catch him or her off guard.