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

C file extension

C/C++ Source Code File

Developer Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CUR file extension

Windows Cursor

System Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

HTML file extension

Hypertext Markup Language File

Web Files

JPG file extension

JPEG Image

Raster Image Files

NES file extension

Nintendo (NES) ROM File

Game Files

PART file extension

Partially Downloaded File

Misc Files

RA file extension

Real Audio File

Audio Files

RSS file extension

Rich Site Summary

Web Files

SDF file extension

Standard Data File

Data Files

VCD file extension

Virtual CD

Disk Image Files

VCF file extension

vCard File

Data Files

WAV file extension

WAVE Audio File

Audio Files

ZIP file extension

Zipped File

Compressed Files