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

ACCDB file extension

Access 2007 Database File

Database Files

AIF file extension

Audio Interchange File Format

Audio Files

APK file extension

Android Package File

Executable Files

ASP file extension

Active Server Page

Web Files

CPP file extension

C++ Source Code File

Developer Files

DMP file extension

Windows Memory Dump

System Files

DOC file extension

Microsoft Word Document

Text Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

IFF file extension

Interchange File Format

Audio Files

JS file extension

JavaScript File

Web Files

PNG file extension

Portable Network Graphic

Raster Image Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

3DM file extension

Rhino 3D Model

3D Image Files