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

MDB file extension

Microsoft Access Database

Database Files

7Z file extension

7-Zip Compressed File

Compressed Files

PPT file extension

PowerPoint Presentation

Data Files

TOAST file extension

Toast Disc Image

Disk Image Files

CS file extension

Visual C# Source Code File

Developer Files

PL file extension

Perl Script

Developer Files

LNK file extension

Windows File Shortcut

System Files

GAM file extension

Saved Game File

Game Files

PS file extension

PostScript File

Vector Image Files

PRF file extension

Outlook Profile File

Settings Files

C file extension

C/C++ Source Code File

Developer Files

DLL file extension

Dynamic Link Library

System Files

AIF file extension

Audio Interchange File Format

Audio Files

SWF file extension

Shockwave Flash Movie

Video Files

VOB file extension

DVD Video Object File

Video Files