A text editor is a type of program used to edit plain text files. These programs are sometimes referred to as "Notepad" software following Microsoft's Notepad. Text editors are provided with operating systems and software development packages, and can be used to change the configuration files, documentation files and source code of the programming language.
Some text editors are small and simple, while others offer extensive and complex functions. For example, the Unix and Unix operating systems have the peak editor (or a variant), but many also include the vi and Emacs editors. Microsoft Windows systems come with simple Notepad, although many people, especially programmers, prefer other editors with more functions. Under the classic Apple Macintosh Mac OS, there was the native SimpleText, which was replaced in Mac OS X by TextEdit, which combines the features of a text editor with those typical of a word processor such as rules, margins and selection of multiple sources . These features are not available simultaneously, but must be changed by the user's command or by the program that automatically determines the type of file.
Most word processors can read and write files in plain text format, allowing them to open saved files from text editors. However, to save these files from a word processor, it is necessary to ensure that the file is written in plain text format, and that any text encoding or BOM settings will not obscure the file for its intended use. Non-WYSIWYG word processors, such as WordStar, lend themselves more easily to the service as text editors, and in fact were commonly used as such during the 1980s. The default file format of these text processors often resembles a markup language, with the basic format being plain text and visual format achieved using control characters without printing or escape sequences. Subsequent word processors, such as Microsoft Word, store their files in binary format and are almost never used to edit plain text files.
