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

AIF file extension

Audio Interchange File Format

Audio Files

ASX file extension

Microsoft ASF Redirector File

Video Files

CPP file extension

C++ Source Code File

Developer Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DOC# file extension

Microsoft Word Document

Text Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

DRV file extension

Device Driver

System Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

EXE file extension

Windows Executable File

Executable Files

HTML file extension

Hypertext Markup Language File

Web Files

M4A file extension

MPEG-4 Audio File

Audio Files

MOV file extension

Apple QuickTime Movie

Video Files

PPT file extension

PowerPoint Presentation

Data Files

RPM file extension

Red Hat Package Manager File

Compressed Files

TMP file extension

Temporary File

Backup Files