Many people start learning piano by practicing hand positions like "holding an egg" or "holding various types of balls," but this can lead to problems. In fact, beginners don't need to rigidly study "hand positioning"; a natural hand position is best.

Firstly, everyone should have a basic understanding of each part of their hands and arms.

Hands:

1. Fingers: Except for the thumb, each finger has three joints, numbered 1, 2, and 3 from fingertip to palm.
2. Palm: The part of the hand that connects to the arm is called the wrist joint.

Arms:

1. Elbow joint: The junction of the forearm and upper arm.
2. Shoulder joint: The junction of the upper arm and the body, with the scapula on the back.

Next, let's look at the functions of each part:

1. The 1st joint: Bears the brunt of all force, must be stable, slightly protruding is preferable.
2. The 2nd joint: Transfers force, but you don't need to focus too much on it.
3. The 3rd joint: The point where force is most directly applied; beginners can treat it as the point for applying force.

A special mention for the thumb: It just needs to lie flat on the keys sideways; excessive force is unnecessary.

Wrist:

It transmits force and facilitates movement. Keep it level, move left and right more, and minimize up and down movements, especially for beginners.

Elbows and shoulders:

Elbows and shoulders should naturally hang down, but don't clamp them against your body!