Most cars have a cam belt, although some do not and some have a chain instead of a rubber belt. If your car has a rubber cam belt then it is advised that you change it every 60,000 miles or when the car reaches 7 years old. When buying a second hand car, many garages recommend that you change the cam belt regardless as you cannot be sure when it was last done. Changing a cam belt can cost less than one hundred pounds, but if the cam belt goes it can render the car worthless and leave you with a vehicle that won’t even start!
People often take their cars to a main dealer to have the cam belt done, and this is often included as part of the major service that should be carried out as specified by the manufacturer. You can of course take the car to a local dealer who may charge you a lot less for the replacement belt and labour. Unless you are extremely confident, I would not suggest changing the cam belt on your car yourself.