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

GAM file extension

Saved Game File

Game Files

VCD file extension

Virtual CD

Disk Image Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

BAK file extension

Backup File

Backup Files

PAGES file extension

Pages Document

Text Files

PL file extension

Perl Script

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

MDB file extension

Microsoft Access Database

Database Files

MPA file extension

MPEG-2 Audio File

Audio Files

CAB file extension

Windows Cabinet File

System Files

ICS file extension

iCalendar File

Misc Files

PIF file extension

Program Information File

Executable Files

DAT file extension

Data File

Data Files

EXE file extension

Windows Executable File

Executable Files