A text file (sometimes spelled “textfile”: an old alternative name is “flatfile”) is a kind of computer file that is structured as a sequence of lines of electronic text. A text file exists within a computer file system. The end of a text file is often denoted by placing one or more special characters, known as an end-of-file marker, after the last line in a text file.
“Text file” refers to a type of container, while plain text refers to a type of content. Text files can contain plain text, but they are not limited to such.
At a generic level of description, there are two kinds of computer files: text files and binary files.
MS-DOS and Windows use a common text file format, with each line of text separated by a two-character combination: CR and LF, which have ASCII codes 13 and 10. It is common for the last line of text not to be terminated with a CR-LF marker, and many text editors (including Notepad) do not automatically insert one on the last line.
Most Windows text files use a form of ANSI, OEM or Unicode encoding. What Windows terminology calls “ANSI encodings” are usually single-byte ISO-8859 encodings, except for in locales such as Chinese, Japanese and Korean that require double-byte character sets. ANSI encodings were traditionally used as default system locales within Windows, before the transition to Unicode. By contrast, OEM encodings, also known as MS-DOS code pages, were defined by IBM for use in the original IBM PC text mode display system. They typically include graphical and line-drawing characters common in (possibly full-screen) MS-DOS applications. Newer Windows text files may use a Unicode encoding such as UTF-16LE or UTF-8, with Byte Order Mark.