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

CFM file extension

ColdFusion Markup File

Web Files

DNG file extension

Digital Negative Image File

Camera Raw Files

SQL file extension

Structured Query Language Data File

Database Files

OTF file extension

OpenType Font

Font Files

LUA file extension

Lua Source File

Developer Files

M3U file extension

Media Playlist File

Audio Files

AZW file extension

Amazon Kindle eBook File

eBook Files

TARGZ file extension

Compressed Tarball File

Compressed Files

FLA file extension

Adobe Flash Animation

Developer Files

GED file extension

GEDCOM Genealogy Data File

Data Files

7Z file extension

7-Zip Compressed File

Compressed Files

COM file extension

DOS Command File

Executable Files

CUE file extension

Cue Sheet File

Disk Image Files

JAR file extension

Java Archive File

Executable Files

ZIP file extension

Zipped File

Compressed Files