A block is a technique used against an attacking weapon, such as an arm, leg, stick, etc, to stop or deflect the attack. Taekwondo is a defensive martial art, so blocks are of primary concern. The main purpose of Taekwondo is to prevent an attacker from harming you or another person. A block performed correctly with focus and power may also serve as an attack since it may do damage to the opponent. If a block is performed correctly, then counterattacks or attacks by you may not be necessary.