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

PRF file extension

Outlook Profile File

Settings Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DBF file extension

Database File

Database Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

RM file extension

Real Media File

Video Files

PIF file extension

Program Information File

Executable Files

PHP file extension

PHP Source Code File

Web Files

PPT file extension

PowerPoint Presentation

Data Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

CUE file extension

Cue Sheet File

Disk Image Files

ICO file extension

Icon File

System Files

DTD file extension

Document Type Definition File

Developer Files

MDB file extension

Microsoft Access Database

Database Files

ASP file extension

Active Server Page

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files