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

AIF file extension

Audio Interchange File Format

Audio Files

CPL file extension

Windows Control Panel Item

System Files

DEB file extension

Debian Software Package

Compressed Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

JSP file extension

Java Server Page

Web Files

NES file extension

Nintendo (NES) ROM File

Game Files

PIF file extension

Program Information File

Executable Files

PL file extension

Perl Script

Developer Files

PY file extension

Python Script

Developer Files

RTF file extension

Rich Text Format File

Text Files

SQL file extension

Structured Query Language Data File

Database Files

TARGZ file extension

Compressed Tarball File

Compressed Files

VOB file extension

DVD Video Object File

Video Files

3DS file extension

3D Studio Scene

3D Image Files

3GP file extension

3GPP Multimedia File

Video Files