Karate, which translates to "empty hand," is the art of unarmed combat. It was first developed in China over a thousand years ago, and was introduced and further developed in Okinawa as a form of weaponless self defense. It was originally practiced in secret by the common people who were not allowed to bear arms. It was not introduced to mainland Japan until the 1920's. In karate, every part of the body can be turned into a fighting weapon, and defensive techniques are used to block an opponents attack. In matches, competitors wear protective uniforms. Points are given to a competitor for kicks and punches to his/her opponent. Also, points are given for series of ritualized movements that are used to judge the athlete's form and concentration. Today, karate has become an internationalized sport, with more than 23 million people participate in karate throughout the world.