'CPU' originates from the term 'Central Processing Unit', where 'central' means 'main or primary', 'processing' refers to 'performing operations on data', and 'unit' means 'a single thing or component'.

The term 'CPU' has been used since the early days of computing to describe the main processing component of a computer.

Initially, it referred to the mainframe computers' processing unit, but now it applies to all types of computers, including personal computers and smartphones.