Judo is a term that refers to the modern version of the Japanese martial art and combat sport. The name, which means "gentle way", evolved in late nineteenth century Japan, and martial arts experts agree that it's most prominent feature lies primarily on its competitive element, and its objectives or main goals are to throw your opponent to the ground, immobilize him/her with a clutching or grappling maneuver, and/or pressing an opponent into submission by employing a choke or locking an elbow. The player's hand and feet move by striking or thrusting an opponent, along with other weapons; however these are only done in a pre-arranged manner, and are disallowed in official judo competitions or free practice, randori.

This martial art form evolved from the art of jiujitsu, referring to a system of hand-to-hand combat. In feudal Japan, the bushi or Samurai were given credit for developing jujutsu, although during the heyday of the Samurai it was referred to as Yoroi kumi-uchi. This early form involved a grappling maneuver, with both opponents fully clad in traditional Japanese armor. As the sport spread throughout the Western world and rapidly began to grow in popularity, it became part of sporting circles, leading to its inclusion as an official Olympic sport in the 1964 Tokyo Games. With the entry of judo as an official Olympic sport, more emphasis was placed into its more physical and competitive aspects, which according to purists and critics, was made at the expense of its moral, intellectual and spiritual foundations.

Over the past century, the official rules of judo competitions have dramatically changed. Initially, the sport of Kodokan Judo was viewed as a form of jujutsu and official competitions were usually held in the older jujutsu style. According to early participants, the competition in those days was tremendously rough, which at times cost some of the players their lives. Competition among different jiujitsu schools was a common sight, and the Kodokan participated in many such challenge matches. The sport's practitioners are called judoka, or judo player. In its early years however, only those ranked 4th Dan or higher were called judoka, but present rules have already been modified. According to sports historians, the suffix -ka, when added to a noun, refers to an individual who is known to possess the expertise or full knowledge of that subject. Today however, the term "judoka" universally refers to any participant or player, irrespective of whether he or she has any particular level of expertise implied.

Playing this ancient sport involves doing a wide array of falls, throws, rolls, chokes, hold-downs, strikes and joint-locks. Experts however point out that main focus of this combat sport is on throwing (nagezawa) and groundwork (ne-waza). The throws are classified into two sets of techniques, and these could either be done through using the standing techniques (tachi-waza), or by using the sacrifice techniques (te-waza).