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

TARGZ file extension

Compressed Tarball File

Compressed Files

XCODEPROJ file extension

Xcode Project

Developer Files

DXF file extension

Drawing Exchange Format File

CAD Files

ICS file extension

iCalendar File

Misc Files

FNT file extension

Windows Font File

Font Files

CSV file extension

Comma Separated Values File

Data Files

ASP file extension

Active Server Page

Web Files

PART file extension

Partially Downloaded File

Misc Files

HTM file extension

Hypertext Markup Language File

Web Files

BMP file extension

Bitmap Image File

Raster Image Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

M3U file extension

Media Playlist File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

PY file extension

Python Script

Developer Files

KMZ file extension

Google Earth Placemark File

GIS Files