Acronym for “central processing unit”. This is the brains of any computer and handles most calculations on a day-to-day basis for basis computer functions. In the early days of bitcoin mining, miners utilized the computational power of their CPUs to mine bitcoins. This was soon surpassed by GPU mining technology as mining difficulty increased to a point where CPU mining was no longer profitable.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc