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

ASP file extension

Active Server Page

Web Files

BIN file extension

Binary Disc Image

Disk Image Files

CGI file extension

Common Gateway Interface Script

Executable Files

CPL file extension

Windows Control Panel Item

System Files

CRX file extension

Chrome Extension

Plugin Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

MAX file extension

3ds Max Scene File

3D Image Files

MPG file extension

MPEG Video File

Video Files

PY file extension

Python Script

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TEX file extension

LaTeX Source Document

Text Files

TORRENT file extension

BitTorrent File

Misc Files

UUE file extension

Uuencoded File

Encoded Files

WPD file extension

WordPerfect Document

Text Files