File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

WPS file extension

Microsoft Works Word Processor Document

Text Files

VCXPROJ file extension

Visual C++ Project

Developer Files

RTF file extension

Rich Text Format File

Text Files

CGI file extension

Common Gateway Interface Script

Executable Files

INI file extension

Windows Initialization File

Settings Files

TIFF file extension

Tagged Image File Format

Raster Image Files

SITX file extension

StuffIt X Archive

Compressed Files

PL file extension

Perl Script

Developer Files

DEB file extension

Debian Software Package

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

CSS file extension

Cascading Style Sheet

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

XML file extension

XML File

Data Files

EXE file extension

Windows Executable File

Executable Files

TTF file extension

TrueType Font

Font Files