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

RA file extension

Real Audio File

Audio Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

MSG file extension

Outlook Mail Message

Text Files

LNK file extension

Windows File Shortcut

System Files

SITX file extension

StuffIt X Archive

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files

PCT file extension

Picture File

Layout Files

ASP file extension

Active Server Page

Web Files

BAT file extension

DOS Batch File

Executable Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

MOV file extension

Apple QuickTime Movie

Video Files

RM file extension

Real Media File

Video Files