CPU Miner
In short: A CPU miner creates or mines cryptocurrency with a computer's central processing unit (CPU), the general-purpose processor found in every PC and server.
A CPU miner creates or mines cryptocurrency with a computer's central processing unit (CPU), the general-purpose processor found in every PC and server. Because mining requires computing power, this approach is called CPU mining, or central processing unit mining, and the name is used both for the people who do it and for the software that runs the calculations.
Why it matters
In Bitcoin's early days, anyone could mine on an ordinary processor. As competition grew, miners moved to graphics cards and then to ASICs, chips built for a single algorithm, and CPU mining of Bitcoin stopped being practical. CPU mining now survives mainly on networks designed to be ASIC-resistant; Monero, for example, uses an algorithm called RandomX that is built to run efficiently on general-purpose processors. The same accessibility has a downside, because criminals can secretly use other people's processors to mine.
Example
A hobbyist installs open-source mining software on a home computer and connects it to a mining pool for a CPU-friendly coin. The pool combines the work of many participants and pays each one a small share of the rewards in proportion to the work submitted. The hobbyist then compares those payouts with the extra electricity the computer uses to decide whether the effort is worthwhile.