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

AVI file extension

Audio Video Interleave File

Video Files

C file extension

C/C++ Source Code File

Developer Files

CGI file extension

Common Gateway Interface Script

Executable Files

DBF file extension

Database File

Database Files

DMP file extension

Windows Memory Dump

System Files

DOC file extension

Microsoft Word Document

Text Files

GADGET file extension

Windows Gadget

Executable Files

IBOOKS file extension

Multi-Touch iBook

Data Files

LNK file extension

Windows File Shortcut

System Files

MAX file extension

3ds Max Scene File

3D Image Files

MDB file extension

Microsoft Access Database

Database Files

MP4 file extension

MPEG-4 Video File

Video Files

TGA file extension

Targa Graphic

Raster Image Files

WPS file extension

Microsoft Works Word Processor Document

Text Files