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

APP file extension

Mac OS X Application

Executable Files

CFG file extension

Configuration File

Settings Files

CSR file extension

Certificate Signing Request File

Web Files

DMP file extension

Windows Memory Dump

System Files

DXF file extension

Drawing Exchange Format File

CAD Files

FLV file extension

Flash Video File

Video Files

GBR file extension

Gerber File

Data Files

M3U file extension

Media Playlist File

Audio Files

PRF file extension

Outlook Profile File

Settings Files

RA file extension

Real Audio File

Audio Files

TMP file extension

Temporary File

Backup Files

TORRENT file extension

BitTorrent File

Misc Files

VOB file extension

DVD Video Object File

Video Files

WPD file extension

WordPerfect Document

Text Files

XLR file extension

Works Spreadsheet

Spreadsheet Files