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

AI file extension

Adobe Illustrator File

Vector Image Files

BAT file extension

DOS Batch File

Executable Files

BIN file extension

Binary Disc Image

Disk Image Files

CFM file extension

ColdFusion Markup File

Web Files

DEM file extension

Video Game Demo File

Game Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

EPUB file extension

Open eBook File

eBook Files

GZ file extension

Gnu Zipped Archive

Compressed Files

MOV file extension

Apple QuickTime Movie

Video Files

MSI file extension

Windows Installer Package

Misc Files

RTF file extension

Rich Text Format File

Text Files

TAR file extension

Consolidated Unix File Archive

Data Files

TIF file extension

Tagged Image File

Raster Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files

XML file extension

XML File

Data Files