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

APK file extension

Android Package File

Executable Files

ASPX file extension

Active Server Page Extended File

Web Files

CBR file extension

Comic Book RAR Archive

Compressed Files

EXE file extension

Windows Executable File

Executable Files

FLV file extension

Flash Video File

Video Files

GBR file extension

Gerber File

Data Files

H file extension

C/C++/Objective-C Header File

Developer Files

ISO file extension

Disc Image File

Disk Image Files

M3U file extension

Media Playlist File

Audio Files

MOBI file extension

Mobipocket eBook

eBook Files

NES file extension

Nintendo (NES) ROM File

Game Files

PNG file extension

Portable Network Graphic

Raster Image Files

PY file extension

Python Script

Developer Files

VCD file extension

Virtual CD

Disk Image Files

ZIPX file extension

Extended Zip File

Compressed Files