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

ASF file extension

Advanced Systems Format File

Video Files

ASP file extension

Active Server Page

Web Files

ASX file extension

Microsoft ASF Redirector File

Video Files

CUE file extension

Cue Sheet File

Disk Image Files

DXF file extension

Drawing Exchange Format File

CAD Files

JPG file extension

JPEG Image

Raster Image Files

PIF file extension

Program Information File

Executable Files

PNG file extension

Portable Network Graphic

Raster Image Files

PPS file extension

PowerPoint Slide Show

Data Files

PPT file extension

PowerPoint Presentation

Data Files

TTF file extension

TrueType Font

Font Files

TXT file extension

Plain Text File

Text Files

UUE file extension

Uuencoded File

Encoded Files

VCF file extension

vCard File

Data Files

3G2 file extension

3GPP2 Multimedia File

Video Files