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

EXE file extension

Windows Executable File

Executable Files

GED file extension

GEDCOM Genealogy Data File

Data Files

HTML file extension

Hypertext Markup Language File

Web Files

ICO file extension

Icon File

System Files

JAR file extension

Java Archive File

Executable Files

KML file extension

Keyhole Markup Language File

GIS Files

LNK file extension

Windows File Shortcut

System Files

LUA file extension

Lua Source File

Developer Files

PNG file extension

Portable Network Graphic

Raster Image Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

RA file extension

Real Audio File

Audio Files

RSS file extension

Rich Site Summary

Web Files

SLN file extension

Visual Studio Solution File

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

TGA file extension

Targa Graphic

Raster Image Files