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

FLV file extension

Flash Video File

Video Files

AI file extension

Adobe Illustrator File

Vector Image Files

PHP file extension

PHP Source Code File

Web Files

CSV file extension

Comma Separated Values File

Data Files

CPP file extension

C++ Source Code File

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

AZW file extension

Amazon Kindle eBook File

eBook Files

KML file extension

Keyhole Markup Language File

GIS Files

PIF file extension

Program Information File

Executable Files

MOV file extension

Apple QuickTime Movie

Video Files

MDB file extension

Microsoft Access Database

Database Files

PCT file extension

Picture File

Layout Files

TORRENT file extension

BitTorrent File

Misc Files

VCD file extension

Virtual CD

Disk Image Files

RA file extension

Real Audio File

Audio Files