A pool can refer to different things. It can be a structure designed to hold water for swimming or other leisure activities, such as an Olympic-size swimming pool

. It can also be a small and rather deep body of water, a continuous area of porous sedimentary rock that yields petroleum or gas, or a group of people or a quantity of a particular thing, such as money, collected together for shared use by several people or organizations

. The term "pool" has various meanings depending on the context in which it is used.