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

MDB file extension

Microsoft Access Database

Database Files

ASPX file extension

Active Server Page Extended File

Web Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files

INI file extension

Windows Initialization File

Settings Files

TAR file extension

Consolidated Unix File Archive

Data Files

PAGES file extension

Pages Document

Text Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

RA file extension

Real Audio File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

VB file extension

VBScript File

Executable Files

ICS file extension

iCalendar File

Misc Files

ASF file extension

Advanced Systems Format File

Video Files

M3U file extension

Media Playlist File

Audio Files