The cars cam-belt is a vital part of the engine as it powers the cam-shaft that regulates the timing of the inlet and exhaust valves in the engine. Unfortunately these belts have a finite lifespan and after about 60,000 miles they are at risk of snapping. Depending on the construction of the engine, this could result in damage to the valves, valve stems and the interior of the combustion chamber which will be very costly to repair.
If you buy a second hand car without a service history indicating that a cam-belt change has been done, you would be well advised to get it changed as soon as possible. While the job is often quite expensive it could be much cheaper than repairing a damaged engine. Happily, many cars now use a chain instead of a belt, which should never snap, so check the cars service schedule to see if a belt change is indicated.