A program used specifically for entry and modification of data that is in a textual format. Such data may be a program written in a high-level language, a report or book written in a natural language, or numerical input for, say, a statistical program.

Text editors form an essential part of the user interface of all interactive systems. They may be line-oriented, where the text is considered to be a series of lines separated by end-of-line markers, character-oriented, where the text is considered to be a stream of characters with any end-of-line or page markers counting as characters, or screen editors. With screen editors, the display screen forms a movable window into the text, within which the cursor may be positioned at points where insertions, deletions, and other editing functions are to be performed.

There is a considerable overlap in function between text editors and word processing systems.