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

ACCDB file extension

Access 2007 Database File

Database Files

AZW file extension

Amazon Kindle eBook File

eBook Files

CS file extension

Visual C# Source Code File

Developer Files

CSS file extension

Cascading Style Sheet

Web Files

CSV file extension

Comma Separated Values File

Data Files

DB file extension

Database File

Database Files

DEM file extension

Video Game Demo File

Game Files

ICS file extension

iCalendar File

Misc Files

JAVA file extension

Java Source Code File

Developer Files

KML file extension

Keyhole Markup Language File

GIS Files

RA file extension

Real Audio File

Audio Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SLN file extension

Visual Studio Solution File

Developer Files

SRT file extension

SubRip Subtitle File

Video Files

WSF file extension

Windows Script File

Executable Files