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

DWG file extension

AutoCAD Drawing Database File

CAD Files

PL file extension

Perl Script

Developer Files

SLN file extension

Visual Studio Solution File

Developer Files

ICS file extension

iCalendar File

Misc Files

MDB file extension

Microsoft Access Database

Database Files

YUV file extension

YUV Encoded Image File

Raster Image Files

GZ file extension

Gnu Zipped Archive

Compressed Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

JAVA file extension

Java Source Code File

Developer Files

RPM file extension

Red Hat Package Manager File

Compressed Files

KML file extension

Keyhole Markup Language File

GIS Files

7Z file extension

7-Zip Compressed File

Compressed Files

ICO file extension

Icon File

System Files

CFM file extension

ColdFusion Markup File

Web Files

SITX file extension

StuffIt X Archive

Compressed Files