Wrestling is a combat sport involving grappling type techniques (takedowns, throws, clinch fighting, joint locks, pins, etc.) in order to gain and maintain a superior position against an opponent.  One of the oldest martial art forms, Wrestling is known currently to be split into two forms: Greco-Roman and Collegiate/Freestyle wrestling.  Greco-Roman style wrestling emphasizes explosive throws and pinning while forbidding grabbing below the belt, tripping the opponent, and using the legs to assist in executing techniques. 

Collegiate/Freestyle wrestling allows the use of legs in both offensive and defensive techniques.  Both disciplines are highly-respected Olympic sports.