When overhand serving a ball in various sports like volleyball, tennis, or badminton, you primarily use the palm of your hand to make contact with the ball. Here's how it typically works in volleyball, which is a common example:

Volleyball Overhand Serve:

1. Grip: To perform an overhand serve in volleyball, stand facing the net with your non-dominant foot forward. Hold the ball in your non-dominant hand and extend your dominant hand above and behind your head, creating a platform with your hand.

2. Contact: As you initiate the serve, use the palm of your dominant hand to make contact with the lower part of the ball, just below its center. Your fingers should be slightly spread, creating a flat surface with your hand.

3. Follow-Through: After making contact, follow through with your serving motion. Your hand should continue to move in the direction you want the ball to go, which is typically over the net and into the opponent's court.

4. Topspin (Optional): In volleyball, players often aim to put topspin on the ball to make it more challenging for the opposing team to receive. To achieve topspin, you strike the ball slightly below the center and follow through with a snapping motion of the wrist.

It's important to note that while the palm of the hand is the primary contact point, the fingers also play a role in providing control and direction to the serve. The specific techniques and nuances of serving can vary depending on the sport and personal preferences, but the use of the palm for contact remains a fundamental aspect of overhand serving.

In tennis and badminton, the overhand serve is executed with similar principles, where the palm is used to make contact with the ball or shuttlecock, respectively, to initiate the serve. The hand position, grip, and follow-through may differ slightly in these sports, but the fundamental concept of palm contact remains consistent.