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

C file extension

C/C++ Source Code File

Developer Files

CS file extension

Visual C# Source Code File

Developer Files

DEB file extension

Debian Software Package

Compressed Files

GED file extension

GEDCOM Genealogy Data File

Data Files

JS file extension

JavaScript File

Web Files

JSP file extension

Java Server Page

Web Files

MDF file extension

Media Disc Image File

Disk Image Files

RA file extension

Real Audio File

Audio Files

RM file extension

Real Media File

Video Files

UUE file extension

Uuencoded File

Encoded Files

VCF file extension

vCard File

Data Files

WAV file extension

WAVE Audio File

Audio Files

WMA file extension

Windows Media Audio File

Audio Files

ZIP file extension

Zipped File

Compressed Files