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

CFM file extension

ColdFusion Markup File

Web Files

CUR file extension

Windows Cursor

System Files

DMP file extension

Windows Memory Dump

System Files

DOC file extension

Microsoft Word Document

Text Files

DXF file extension

Drawing Exchange Format File

CAD Files

FNT file extension

Windows Font File

Font Files

GADGET file extension

Windows Gadget

Executable Files

ISO file extension

Disc Image File

Disk Image Files

M file extension

Objective-C Implementation File

Developer Files

MAX file extension

3ds Max Scene File

3D Image Files

PAGES file extension

Pages Document

Text Files

PIF file extension

Program Information File

Executable Files

TEX file extension

LaTeX Source Document

Text Files

3G2 file extension

3GPP2 Multimedia File

Video Files