Technical writing, a form of technical communication, is a style of writing used in fields as diverse as computer hardware and software, engineering, chemistry, the aerospace industry, robotics, finance, consumer electronics, and biotechnology. wikipedia.org

A technical writer (also called a technical communicator) is a professional writer who engages in technical writing wherein he or she designs, creates, and maintains technical documentation. wikipedia.org

Technical editing involves reviewing text written on a technical topic, and identifying usage errors and ensuring adherence to a style guide.

Proofreading (also proof-reading) is the reading of a galley proof or computer monitor to detect and correct production-errors of text or art. Proofreaders are expected to be consistently accurate by default because they occupy the last stage of typographic production before publication. wikipedia.org

An article is a written work published in a print or electronic medium. It may be for the purpose of propagating the news, research results, academic analysis or debate. wikipedia.org