Technical writing is writing or drafting technical communication used in technical and occupational fields, such as computer hardware and software, architecture, engineering, chemistry, aeronautics, robotics, finance, medical, consumer electronics, biotechnology, and forestry. Technical writing encompasses the largest sub-field in technical communication.

The Society for Technical Communication defines technical communication as any form of communication that exhibits one or more of the following characteristics: "(1) communicating about technical or specialized topics, such as computer applications, medical procedures, or environmental regulations; (2) communicating by using technology, such as web pages, help files, or social media sites; or (3) providing instructions about how to do something, regardless of how technical the task is".