Martial Arts is a term that is used for various forms of combat, self defense, and sport combat. This can include both unarmed and armed. Although many think of the Eastern disciplines when you hear the words Martial Arts, it really includes all forms of combat from many regions of the world. For example, Fencing and Boxing would be a martial arts from the West.
Although Martial Arts is listed under the Sports category, it is much more and many disciplines are used for recreation, health/fitness, military training, spirituality, and of course self defense to name a few.