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

ASF file extension

Advanced Systems Format File

Video Files

DDS file extension

DirectDraw Surface

Raster Image Files

EXE file extension

Windows Executable File

Executable Files

FLA file extension

Adobe Flash Animation

Developer Files

FLV file extension

Flash Video File

Video Files

GZ file extension

Gnu Zipped Archive

Compressed Files

HTM file extension

Hypertext Markup Language File

Web Files

MDB file extension

Microsoft Access Database

Database Files

MID file extension

MIDI File

Audio Files

MP3 file extension

MP3 Audio File

Audio Files

PAGES file extension

Pages Document

Text Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TOAST file extension

Toast Disc Image

Disk Image Files

VCF file extension

vCard File

Data Files