A punch is a simple thing, even babies punch when they are upset. When a person is angered, a punch is usually the first physical thing that happens, usually directed at something or someone. Usually, the punching hand is injured as much as the person or thing that was struck, sometimes more. Punching is highly effective and deadly if done properly.
Some taekwondo organizations, such as the World Taekwondo (WT), want to separate taekwondo from its karate roots and the influences other martial arts had on its development so they stress kicking and practically ignore punching, which is stressed in karate and most other martial arts. However, self-defense is not a sport; to be a well-rounded fighter, you must be proficient with both your arms and legs. When surprised by an attacker on the street and you must instantly react, you will react in the way you have done the most training. If your training has been mostly dancing around with your hands at your sides, then—good luck.
About punches: Some interesting information about punching.
History of punching: How something so simple became complicated.
Punch physics: Physics behind the punch.
Power punchers: Punchers who were known for their power.
Bare-knuckle punching: Punching without gloves.
To punch or not to punch: Sometimes a palm heel strike is better.
Horizontal vs. vertical fist: A detailed analysis of the two punching methods.
Twisting a punch: Twisting a punch for power and safety.
Sequence of forces: Many forces coming together at impact.
Lock-out vs. snap-back: Two ways to throw a punch.
Pulling punches: We don't pull punches.
Focused vs. follow-through: Which is more effective?
Cocking a punch: Cocking (cambering) a punch and using pullback for power.
Push-pull: Which happens first?
Types of fists: Some of the ways to make a fist.
Fist clenching: When to clench the fist.
Hand and wrist alignment: Keep everything straight.
Hand strength: A strong grip adds to a strong punch.
Head tilt: Tilt the head for power.
Telegraphing a punch: Any movement that alerts your opponent to your attack
Headhunting: Concentrating on punching the head and not the body.
Body shots: Hurt the body, kill the head.
Extended punch: For maximum power, extend punches.
Punching basics: Things common to all punches.
Fore-fist/straight punch: The basic straight punch.
Jab punch: A quick and leading hand straight punch.
Cross punch: A trailing hand straight punch.
Hook punch: If you can't get through a guard, go around it.
Uppercut punch: A powerful, knockout punch.
Other punches: Some other types of punches.
Punching tips: Tips for better punching.