Re: this may be a stupind question
You use the power of your CPU (and GPU) to calculate complicated equations that lead to "mining" virtual currency, such as Bitcoin.
You can definitely start mining at home with your home computer by looking into the World Community Grid. I've been mining with them for a few months, but I do it for various open-source and health-related projects. On the side,*I make some virtual currency (Ripples, XRP).
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