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

ASP file extension

Active Server Page

Web Files

BIN file extension

Binary Disc Image

Disk Image Files

DBF file extension

Database File

Database Files

DLL file extension

Dynamic Link Library

System Files

DTD file extension

Document Type Definition File

Developer Files

FLV file extension

Flash Video File

Video Files

INDD file extension

Adobe InDesign Document

Layout Files

MOV file extension

Apple QuickTime Movie

Video Files

PPS file extension

PowerPoint Slide Show

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SQL file extension

Structured Query Language Data File

Database Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TGA file extension

Targa Graphic

Raster Image Files

VCF file extension

vCard File

Data Files

ZIPX file extension

Extended Zip File

Compressed Files