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

DOCX file extension

Microsoft Word Open XML Document

Text Files

KML file extension

Keyhole Markup Language File

GIS Files

BMP file extension

Bitmap Image File

Raster Image Files

DRV file extension

Device Driver

System Files

ZIP file extension

Zipped File

Compressed Files

7Z file extension

7-Zip Compressed File

Compressed Files

DLL file extension

Dynamic Link Library

System Files

TORRENT file extension

BitTorrent File

Misc Files

SH file extension

Bash Shell Script

Developer Files

WMA file extension

Windows Media Audio File

Audio Files

DNG file extension

Digital Negative Image File

Camera Raw Files

UUE file extension

Uuencoded File

Encoded Files

BIN file extension

Binary Disc Image

Disk Image Files

DB file extension

Database File

Database Files

CBR file extension

Comic Book RAR Archive

Compressed Files