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

GPX file extension

GPS Exchange File

GIS Files

ICNS file extension

Mac OS X Icon Resource File

System Files

AI file extension

Adobe Illustrator File

Vector Image Files

WMV file extension

Windows Media Video File

Video Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

CUR file extension

Windows Cursor

System Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

DB file extension

Database File

Database Files

7Z file extension

7-Zip Compressed File

Compressed Files

VCXPROJ file extension

Visual C++ Project

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

C file extension

C/C++ Source Code File

Developer Files

PPT file extension

PowerPoint Presentation

Data Files

APK file extension

Android Package File

Executable Files