What is the difference between flush tank, and flush valve? and for which type of buildings flush valve is preferred?

A Flush tank and Flush valve is differentiated based on its application. Flush valve is used in public building, where water should be available for use Instantaneously. Flush tank can be used in building where there is not that much rush into the toilets.

flush valve is a mechanism used to flush a toilet or urinal while a flush tank  holds fluid in reserve for flushing type of building flush valve is preferred is mall, supermarket, cinemas,clubs and public toilet