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

UUE file extension

Uuencoded File

Encoded Files

PPT file extension

PowerPoint Presentation

Data Files

CPL file extension

Windows Control Panel Item

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

ZIPX file extension

Extended Zip File

Compressed Files

APK file extension

Android Package File

Executable Files

AZW file extension

Amazon Kindle eBook File

eBook Files

MSI file extension

Windows Installer Package

Misc Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

FON file extension

Generic Font File

Font Files

PART file extension

Partially Downloaded File

Misc Files

FLV file extension

Flash Video File

Video Files

M3U file extension

Media Playlist File

Audio Files

COM file extension

DOS Command File

Executable Files

DBF file extension

Database File

Database Files