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

CGI file extension

Common Gateway Interface Script

Executable Files

CPP file extension

C++ Source Code File

Developer Files

FLV file extension

Flash Video File

Video Files

GAM file extension

Saved Game File

Game Files

GBR file extension

Gerber File

Data Files

GZ file extension

Gnu Zipped Archive

Compressed Files

MAX file extension

3ds Max Scene File

3D Image Files

MP3 file extension

MP3 Audio File

Audio Files

PKG file extension

Mac OS X Installer Package

Compressed Files

PL file extension

Perl Script

Developer Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SRT file extension

SubRip Subtitle File

Video Files

SWF file extension

Shockwave Flash Movie

Video Files

WSF file extension

Windows Script File

Executable Files

YUV file extension

YUV Encoded Image File

Raster Image Files