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

OBJ file extension

Wavefront 3D Object File

3D Image Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

FON file extension

Generic Font File

Font Files

VCD file extension

Virtual CD

Disk Image Files

ODT file extension

OpenDocument Text Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

DRV file extension

Device Driver

System Files

WMA file extension

Windows Media Audio File

Audio Files

PRF file extension

Outlook Profile File

Settings Files

TEX file extension

LaTeX Source Document

Text Files

APP file extension

Mac OS X Application

Executable Files

VB file extension

VBScript File

Executable Files

HTM file extension

Hypertext Markup Language File

Web Files

SLN file extension

Visual Studio Solution File

Developer Files

MDB file extension

Microsoft Access Database

Database Files