What is the difference between attemperator and de-superheater in boiler ?

Attemporator is used to keep the temperatures of steam in the final stages to certain desired limits. This is to protect the super heater, generally two types one kept under the water level- water cooled,
air-cooled kept in the draft line of FD fan. De super heaters are used to reduce the temperatures of a part of steam so that it can be used for auxiliary purposes. two types- surface type( attemperators like) and spray type