Group of individual computers that are connected and work together in mining a cryptocurrency so to be competitive with industrial-size miners. Each computer contributes its power and receives a small portion of what is mined. The mining pool distributes the work among the different computers so that they don’t do double work. Keeps track of how much power is offered and calculates the amount of reward for each participant. It works like a lottery pool: if the pool wins, the amount won is distributed proportionally to the contribution of each member of the pool.