Part of the Computing fundamentals glossary:

1) In computer operating systems, a file name extension is an optional addition to the file name in a suffix of the form ".xxx" where "xxx" represents a limited number of alphanumeric characters depending on the operating system. (In Windows 3.1, for example, a file name extension or suffix can have no more than three characters, but in Windows 95 and later, it can have more.) The file name extension allows a file's format to be described as part of its name so that users can quickly understand the type of file it is without having to "open" or try to use it. The file name extension also helps an application program recognize whether a file is a type that it can work with.

2) In programming, an extension is a file containing programming that serves to extend the capabilities of or data available to a more basic program. Extensions are sometimes required to be stored in a separate extensions file so that they're easy to locate. When installing software, you may be instructed to take one or more steps related to installing extensions (or these steps may automatically be done for you).

This was last updated in September 2005
Contributor(s): Peter Tucker
Posted by: Margaret Rouse

Related Terms

Definitions

  • disruptive technology

    - A disruptive technology is one that displaces an established technology and shakes up the industry. Harvard Business School professor Clayton M. Christensen coined the term.  In his 1997 best-sell... (WhatIs.com)

  • application program interface (API)

    - An application program interface (API) is code that allows two software programs to communicate with each other. Typically, APIs are released for third-party development as part of a software devel... (SearchExchange.com)

  • Microsoft Windows Control Panel

    - The Microsoft Windows Control Panel is a management tool for the Windows operating system (OS) that allows end users to change settings and manage tasks within the OS.  (SearchWindowsServer.com)

Glossaries

  • Computing fundamentals

    - Terms related to computer fundamentals, including computer hardware definitions and words and phrases about software, operating systems, peripherals and troubleshooting.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.