A liquid cooling system (LCS) circulates liquid through small pipes in a heat sink attached to the processor in your system. As the liquid passes through the heat sink, heat from the hot processor is transferred to the cooler liquid. The warmed liquid is then cycled to a radiator on the side or rear of the casing where it is released into the ambient air outside of the unit. The cooled liquid then travels back through the system to the CPU to continue the process.
Over traditional air-cooled systems, some advantages and benefits of a LCS include more efficient cooling and less noise when the system is running. The disadvantage is that liquid cooling can be quite complex, costly, and it requires more maintenance than traditional air-cooled systems.