*Law rubs his forehead, not expecting Minato's punch to come that fast*
Alright, the hands are used in a number of ways in martial arts and combat, whether it be for grappling, punching, chopping or defense. The most common way is a punch. Punches are simply strikes with a closed fist, the power of which depends largely on the individual's skill and strength. Punches range from jabs, to hooks, to uppercuts. The most common combat that utilizes punches is boxing, which employs punching as the only allowed means of striking your opponent.
Another way to utilize the hands is the means of grappling, which are maneuvers that are used to gain an advantage over your opponent by using physical strength to take control of your positions. Grappling can be used to place opponents in submission locks, to escape submission locks or other grapples, and to take down the enemy. However, the hands aren't the only parts used in grappling, the feet are too, so it's used comparably less to that of boxing.
A common use of the hands is an open-hand strikes. As the name suggests, when used, the hand is not closed into a fist. This is used in karate, the most notable and famous being the karate chop. Other styles include spear-hand, which involves holding the fingers straight and keeping them compressed together and then thrusting it directly towards the weak spots of opponents, the neck being an ideal place to strike with this technique. Another use is cupping your hands and then striking the opponent's ears, which can damage the eardrums and leave them off-balanced due to a strike that could hurt the inner ear. For instances when you don't want to injure or damage your knuckles, a strike with the heel of the hand is ideal.