A central processing unit (CPU) miner is simply a CPU used for cryptocurrency mining. A CPU is an electronic circuit that on a device can process or run multiple tasks or programs. Although CPUs are versatile and multi-purpose, they are not as efficient or cost-effective at mining cryptocurrency as purpose-built crypto miners. However, there are a variety of CPUs available, each with its own price point and mining performance characteristics. Some coins and blockchains are specifically designed and optimized for CPU mining.