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

GPX file extension

GPS Exchange File

GIS Files

APP file extension

Mac OS X Application

Executable Files

DBF file extension

Database File

Database Files

HTML file extension

Hypertext Markup Language File

Web Files

RSS file extension

Rich Site Summary

Web Files

MP3 file extension

MP3 Audio File

Audio Files

ACCDB file extension

Access 2007 Database File

Database Files

GADGET file extension

Windows Gadget

Executable Files

VB file extension

VBScript File

Executable Files

NES file extension

Nintendo (NES) ROM File

Game Files

PCT file extension

Picture File

Layout Files

VCF file extension

vCard File

Data Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

JAVA file extension

Java Source Code File

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files