Self-defense methods are techniques used to protect oneself from physical harm. Two popular martial arts used for self-defense are Judo and Karate. Judo is a Japanese martial art that focuses on using an opponent's strength against them. Karate is a Japanese martial art that emphasizes striking techniques such as punches, kicks, and blocks. Jujitsu is another Japanese martial art that focuses on grappling techniques such as throws, joint locks, and submission holds. All three of these martial arts can be used effectively for self-defense.