A water cooling system is made up of the following parts:
1. the water block attached to the CPU (a metal heatsink with water pipes looping around inside it)
2. the water reservoir (to hold water)
3. the radiator (to cool the water down, will normally have large slow fans on it for this)
4. the water pump
5. pipes connecting all of the above
More extreme water cooling systems may use a peltier (thermo-electric) element between the CPU and the water block.
1. the water block attached to the CPU (a metal heatsink with water pipes looping around inside it)
2. the water reservoir (to hold water)
3. the radiator (to cool the water down, will normally have large slow fans on it for this)
4. the water pump
5. pipes connecting all of the above
More extreme water cooling systems may use a peltier (thermo-electric) element between the CPU and the water block.