Tile saws utilize a water pump to pump clean water onto the blade and cutting material in order to lubricate and cool. There is a tub that retains the water from cutting. The pump should always be used with clean water and not allowed to re-circulate the dirty water in order to prevent damage to the water pump. It is also important to keep the unit from freezing. These saws are used to make clean, straight cuts to ceramic and some glass tiles.