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

AZW file extension

Amazon Kindle eBook File

eBook Files

ODT file extension

OpenDocument Text Document

Text Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

RTF file extension

Rich Text Format File

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

PL file extension

Perl Script

Developer Files

ASPX file extension

Active Server Page Extended File

Web Files

3DM file extension

Rhino 3D Model

3D Image Files

VCF file extension

vCard File

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TORRENT file extension

BitTorrent File

Misc Files

RPM file extension

Red Hat Package Manager File

Compressed Files

DOC# file extension

Microsoft Word Document

Text Files

PCT file extension

Picture File

Layout Files