A Batarang is a roughly bat-shaped throwing weapon used by Batman as a non-lethal ranged attack alternative to firearms, which he rejects outright due to the circumstances of his parents' murder. Batman would later train Robin in their use and likewise Batgirl would also learn of them. Batarangs are one of the many gadgets kept in batman's Utility Belt.
The name batarang is a moniker of both bat and "boomerang", a similair throwing device which will return to the thrower. Batman learned many forms of martial arts during his training in Japan, where similair devices called "shuriken" are used in the discipline of Ninjitsu. However it is unknown if Batman studied this art specifically.