Tae Kwon Do is an art form, sport and method of self-defense.  It is an ancient art. It was devised to strengthen an individual's weaknesses and limitations, mentally and physically. 

"Tae" means "to kick or squash with the foot", "Kwon" means a hand or fist to block, punch, strike or destroy, "Do" means an "art or way".  Thus, "Tae Kwon Do" means the art of kicking, blocking and punching.