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

ROM file extension

N64 Game ROM File

Game Files

LNK file extension

Windows File Shortcut

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

GAM file extension

Saved Game File

Game Files

VCF file extension

vCard File

Data Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

MOV file extension

Apple QuickTime Movie

Video Files

ISO file extension

Disc Image File

Disk Image Files

RSS file extension

Rich Site Summary

Web Files

MDB file extension

Microsoft Access Database

Database Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

APP file extension

Mac OS X Application

Executable Files

GZ file extension

Gnu Zipped Archive

Compressed Files

CUR file extension

Windows Cursor

System Files

VB file extension

VBScript File

Executable Files