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

AIF file extension

Audio Interchange File Format

Audio Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

FNT file extension

Windows Font File

Font Files

ICO file extension

Icon File

System Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

PL file extension

Perl Script

Developer Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RA file extension

Real Audio File

Audio Files

SLN file extension

Visual Studio Solution File

Developer Files

TEX file extension

LaTeX Source Document

Text Files

TIF file extension

Tagged Image File

Raster Image Files

TIFF file extension

Tagged Image File Format

Raster Image Files

ZIPX file extension

Extended Zip File

Compressed Files