Final answer:
Desalination is most commonly used in places where freshwater is scarce. This process removes salt from seawater to produce freshwater for drinking.
Step-by-step explanation:
Desalination is most commonly used in places where freshwater is scarce. This includes coastal desert countries like the United Arab Emirates, Bahrain, and Qatar, as well as areas with limited water supply, such as southern California. The process of desalination, particularly through reverse osmosis, removes salt from seawater to produce freshwater that can be used for drinking.