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

CFG file extension

Configuration File

Settings Files

CLASS file extension

Java Class File

Developer Files

DAT file extension

Data File

Data Files

DMP file extension

Windows Memory Dump

System Files

DNG file extension

Digital Negative Image File

Camera Raw Files

DXF file extension

Drawing Exchange Format File

CAD Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

ICO file extension

Icon File

System Files

ICS file extension

iCalendar File

Misc Files

JPG file extension

JPEG Image

Raster Image Files

PS file extension

PostScript File

Vector Image Files

RA file extension

Real Audio File

Audio Files

VCD file extension

Virtual CD

Disk Image Files

WPD file extension

WordPerfect Document

Text Files