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

ACCDB file extension

Access 2007 Database File

Database Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CFM file extension

ColdFusion Markup File

Web Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DMP file extension

Windows Memory Dump

System Files

EXE file extension

Windows Executable File

Executable Files

GBR file extension

Gerber File

Data Files

INDD file extension

Adobe InDesign Document

Layout Files

M file extension

Objective-C Implementation File

Developer Files

M3U file extension

Media Playlist File

Audio Files

PHP file extension

PHP Source Code File

Web Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SYS file extension

Windows System File

System Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

3GP file extension

3GPP Multimedia File

Video Files