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

ASX file extension

Microsoft ASF Redirector File

Video Files

AZW file extension

Amazon Kindle eBook File

eBook Files

COM file extension

DOS Command File

Executable Files

DTD file extension

Document Type Definition File

Developer Files

FLV file extension

Flash Video File

Video Files

FON file extension

Generic Font File

Font Files

GPX file extension

GPS Exchange File

GIS Files

MDB file extension

Microsoft Access Database

Database Files

PDB file extension

Program Database

Database Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

PRF file extension

Outlook Profile File

Settings Files

RTF file extension

Rich Text Format File

Text Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TMP file extension

Temporary File

Backup Files

WMA file extension

Windows Media Audio File

Audio Files