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

HTML file extension

Hypertext Markup Language File

Web Files

JPG file extension

JPEG Image

Raster Image Files

LUA file extension

Lua Source File

Developer Files

MSG file extension

Outlook Mail Message

Text Files

PDB file extension

Program Database

Database Files

PHP file extension

PHP Source Code File

Web Files

PIF file extension

Program Information File

Executable Files

PPT file extension

PowerPoint Presentation

Data Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SLN file extension

Visual Studio Solution File

Developer Files

VCF file extension

vCard File

Data Files

YUV file extension

YUV Encoded Image File

Raster Image Files

ZIPX file extension

Extended Zip File

Compressed Files