A word processor (WP) is a device or computer program that provides for input, editing, formatting, and output of text, often with some additional features.

Early word processors were stand-alone devices dedicated to the function, but current word processors are word processor programs running on general purpose computers, including smartphones, tablets, laptops and desktop computers.

The functions of a word processor program are typically between those of a simple text editor and a desktop publishing program. Many word processing programs have gained advanced features over time providing similar functionality to desktop publishing programs.

Common word processor programs include LibreOffice Writer, Google Docs and Microsoft Word.

Word processors developed from mechanical machines, later merging with computer technology. The history of word processing is the story of the gradual automation of the physical aspects of writing and editing, and then to the refinement of the technology to make it available to corporations and Individuals.

The term word processing appeared in American offices in the early 1970s centered on the idea of streamlining the work to typists, but the meaning soon shifted toward the automation of the whole editing cycle.

At first, the designers of word processing systems combined existing technologies with emerging ones to develop stand-alone equipment, creating a new business distinct from the emerging world of the personal computer. The concept of word processing arose from the more general data processing, which since the 1950s had been the application of computers to business administration.

Through history, there have been three types of word processors: mechanical, electronic and software.