Timing chains are much more used in modern cars than timing belts. Although the latter is often quieter and less expensive, it also tended to require replacement on a far more frequent basis. Depending on the vehicle model, some timing belts need replacing every 50,000 to 70,000 miles. However, timing chains can last far longer because of their more durable construction. Nevertheless, it is important to be familiar with the warning signs of a failing timing chain so you can replace it before severe damage is done to the engine. Plus, if you know how to replace it as well, you can save a lot of money.
(Note: The procedure listed here was performed on a 1993 Lexus ES300 V6, which is a non-interference engine. The engine is arranged in a front wheel drive, transverse configuration, which is typical for many types of cars with timing belts of the era. The instructions will be similar on nearly any front wheel drive car with a timing belt. As always, exercise extreme caution when working on a car. If you're not confident in your mechanical abilities, consult a professional.)