Martial arts are systems of codified practices and traditions of training for combat. While they may be studied for various reasons, martial arts share a single objective: to defeat one or more people physically and to defend oneself or others from physical threat.

In addition, some martial arts have a spiritual or non-spiritual code of honour. Many arts are also practised competitively, most commonly as combat sports.

While each style has unique features that differentiate it from other martial arts, a common characteristic is the systemization of fighting techniques. Methods of training vary and may include sparring or forms (kata), which are routines or techniques that are performed alone, or with a partner.

Kata is a Japanese word describing detailed choreographed patterns of movements practiced either solo or in pairs. Kata are used in many Japanese martial arts, such as Judo, Jiu Jitsu and Karate. Other arts such as Tai Chi Ch'uan and Taekwondo feature the same kind of training, but use the respective Chinese and Korean words instead.

Martial arts vary widely, and may focus on a specific area or combination of areas, but they can be broadly grouped into focusing on strikes, grappling, or weapons training. For example, judo and Brazilian Jiu Jitsu focus on grappling, while Karate and Taekwondo focus on striking.