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

AI file extension

Adobe Illustrator File

Vector Image Files

ASP file extension

Active Server Page

Web Files

AZW file extension

Amazon Kindle eBook File

eBook Files

BMP file extension

Bitmap Image File

Raster Image Files

FON file extension

Generic Font File

Font Files

MPA file extension

MPEG-2 Audio File

Audio Files

MSG file extension

Outlook Mail Message

Text Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PPT file extension

PowerPoint Presentation

Data Files

RA file extension

Real Audio File

Audio Files

SWF file extension

Shockwave Flash Movie

Video Files

UUE file extension

Uuencoded File

Encoded Files

WMA file extension

Windows Media Audio File

Audio Files

XML file extension

XML File

Data Files

ZIPX file extension

Extended Zip File

Compressed Files