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

AVI file extension

Audio Video Interleave File

Video Files

CSV file extension

Comma Separated Values File

Data Files

CUR file extension

Windows Cursor

System Files

DRV file extension

Device Driver

System Files

GAM file extension

Saved Game File

Game Files

GBR file extension

Gerber File

Data Files

GPX file extension

GPS Exchange File

GIS Files

ICO file extension

Icon File

System Files

MDF file extension

Media Disc Image File

Disk Image Files

PCT file extension

Picture File

Layout Files

PIF file extension

Program Information File

Executable Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SQL file extension

Structured Query Language Data File

Database Files

VCXPROJ file extension

Visual C++ Project

Developer Files

3DM file extension

Rhino 3D Model

3D Image Files