Many things can cause an engine to overheat.The first obvious thing to check is the coolant level. Check the coolant both in the coolant expansion tank and radiator when the engine is "cold". On most vehicles the water pump is driven by the timing belt or chain, but if your engine uses an externally driven belt to drive the water pump visually check that it is present and tensioned correctly. If there is coolant loss the source of the leak needs to be found and repaired. A thermostat the has stuck closed not allowing engine coolant to circulate to the radiator will cause over heating, if the cooling fan does not engage when the engine has exceeded normal operating temperature that would cause over heating, radiator that is restricted, or a blown head gasket can all cause over heating conditions.