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

TIFF file extension

Tagged Image File Format

Raster Image Files

TAR file extension

Consolidated Unix File Archive

Data Files

CRX file extension

Chrome Extension

Plugin Files

7Z file extension

7-Zip Compressed File

Compressed Files

TTF file extension

TrueType Font

Font Files

AZW file extension

Amazon Kindle eBook File

eBook Files

VCF file extension

vCard File

Data Files

RTF file extension

Rich Text Format File

Text Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

3DM file extension

Rhino 3D Model

3D Image Files

DB file extension

Database File

Database Files

ZIP file extension

Zipped File

Compressed Files

M3U file extension

Media Playlist File

Audio Files

MSI file extension

Windows Installer Package

Misc Files

DTD file extension

Document Type Definition File

Developer Files