Tennis is a very popular sport in which both players use a tennis racket to hit a small ball around the court, and the player with the highest score wins.

Here is some basic knowledge about tennis:

1. The court: The tennis court is 23.77 meters long and 8.23 meters wide, with a net of 91.4 cm in height in the center, dividing the court into two halves.

2. Racket: Tennis tournaments use special tennis rackets, usually made of wood, aluminum, carbon fiber, and other materials, with certain regulations on weight and size.

3. Ball: Tennis tournaments use yellow woolen balls, 6.7-6.9 cm in diameter and 56.7-58.5 grams in weight.

4. Terminology: There are many terminologies used in tennis, such as serve, receive, swing, winning shot, etc.

Tennis is a sport that requires agility, strength, and stamina.

Players need to master the proper hitting techniques and during the match, players should always be aware of the position and speed of the ball and take the appropriate action at the right time.

To play tennis well, one needs to master the following skills and considerations:

1. Correct stance and posture: stand in the correct position, keep your body balanced, feet apart shoulder-width apart, body weight on the front foot, body relaxed, hands on the racket handle, racket head up, ready to hit the ball.

2. Accurate serve: The serve is a key part of the tennis game, to play tennis well, you must master accurate serving skills. When serving, pay attention to the power and angle control, and make it as difficult as possible for the opponent to receive the serve.

3. Accurate catching: When catching the ball, keep your eyes on the ball, your hands on the racket, and your body stable, pay attention to the opponent's ball path and ball speed, adjust your stance, and hit the ball accurately.

4. Flexible movement: The tennis game requires constant movement to prepare for a catch or a return shot, so learn to move flexibly, adjust to the opponent's ball path and ball speed, and maintain good vision and body balance.

5. Control the power and angle: In the process of returning the ball, adjust the power and angle according to the opponent's ball path and ball speed at the right time, so that the ball can land accurately on the opponent's backhand or forehand area.

6. Stay patient and calm: It is very important to stay patient and calm in a tennis match. Learn to control your emotions, don't lose confidence because of one or two mistakes, stay patient and calm, and keep adjusting your tactics and strategies.

7. Practice more: Finally, to play tennis well you also need to practice more. Only through continuous practice and practice can you master various skills and techniques and improve your level. You can find an experienced coach for guidance, or participate in some tennis courses or tournaments to continuously improve your level.