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

CLASS file extension

Java Class File

Developer Files

CS file extension

Visual C# Source Code File

Developer Files

EXE file extension

Windows Executable File

Executable Files

JS file extension

JavaScript File

Web Files

KMZ file extension

Google Earth Placemark File

GIS Files

PART file extension

Partially Downloaded File

Misc Files

PDB file extension

Program Database

Database Files

PIF file extension

Program Information File

Executable Files

PL file extension

Perl Script

Developer Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RA file extension

Real Audio File

Audio Files

TGA file extension

Targa Graphic

Raster Image Files

TTF file extension

TrueType Font

Font Files

VB file extension

VBScript File

Executable Files

WSF file extension

Windows Script File

Executable Files