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

AZW file extension

Amazon Kindle eBook File

eBook Files

CUR file extension

Windows Cursor

System Files

DOC file extension

Microsoft Word Document

Text Files

GADGET file extension

Windows Gadget

Executable Files

GAM file extension

Saved Game File

Game Files

GBR file extension

Gerber File

Data Files

ICS file extension

iCalendar File

Misc Files

MOV file extension

Apple QuickTime Movie

Video Files

NES file extension

Nintendo (NES) ROM File

Game Files

OTF file extension

OpenType Font

Font Files

PAGES file extension

Pages Document

Text Files

SAV file extension

Saved Game

Game Files

SRT file extension

SubRip Subtitle File

Video Files

VB file extension

VBScript File

Executable Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files