Golf Info Guide has an online chart that lists the compression rating of a range of popular golf balls. The amount a golf ball compresses affects its speed and flight characteristics.
Golf balls that compress more typically travel farther than stiffer golf balls. Because of this, experts recommend high-compression golf balls for players with a low swing speed. While the benefits of low-compression golf balls also apply to golfers with faster swings, compression can make the ball spin more, making it difficult to control. Golfers who get plenty of distance off of their tee shots might prefer a low compression ball for better predictability.