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

ASF file extension

Advanced Systems Format File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CUR file extension

Windows Cursor

System Files

DB file extension

Database File

Database Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

GBR file extension

Gerber File

Data Files

HTML file extension

Hypertext Markup Language File

Web Files

M3U file extension

Media Playlist File

Audio Files

M4V file extension

iTunes Video File

Video Files

OTF file extension

OpenType Font

Font Files

PHP file extension

PHP Source Code File

Web Files

PPS file extension

PowerPoint Slide Show

Data Files

ROM file extension

N64 Game ROM File

Game Files

RSS file extension

Rich Site Summary

Web Files