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

AVI file extension

Audio Video Interleave File

Video Files

CS file extension

Visual C# Source Code File

Developer Files

CUR file extension

Windows Cursor

System Files

EPUB file extension

Open eBook File

eBook Files

EXE file extension

Windows Executable File

Executable Files

FLA file extension

Adobe Flash Animation

Developer Files

HTM file extension

Hypertext Markup Language File

Web Files

IBOOKS file extension

Multi-Touch iBook

Data Files

NES file extension

Nintendo (NES) ROM File

Game Files

PNG file extension

Portable Network Graphic

Raster Image Files

PPS file extension

PowerPoint Slide Show

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

RM file extension

Real Media File

Video Files

SLN file extension

Visual Studio Solution File

Developer Files

WPS file extension

Microsoft Works Word Processor Document

Text Files