Firstly what is flash? Well Flash refers to both the Macromedia Flash Player and to a multimedia authoring program used to create content it (such as games and movies). The Flash Player is a client application available in most web browsers. It features support for vector and raster graphics, a scripting language called ActionScript and bidirectional streaming of audio and video.
Macromedia Flash is the integrated development environment (IDE) and Flash Player is the virtual machine used to run the Flash files, but nowdays these terms have become mixed: "Flash" can mean either the authoring environment, the player, or the application files.
Since its introduction in 1996, Flash technology has become a very popular method for adding animation and interactivity to web pages. Flash can be used to create fantastic animations; to design web-page elements and also to add video to web sites. Websites made with flash can be much more interactive and flashier (pardon the pun) than site made with only html.
The Flash files, or "flash movies", typically have a .swf file extension and may appear as an element of a web page or to be "played" in the standalone Flash Player. For more information visit [http://www.webdesign-resource.info]
Due to wide usage of Flash in web advertisements and the extra time it takes to load these pages, tools have emerged for blocking Flash content in some or all web sites, or temporarily or permanently turning Flash Player off, such as FlashBlock and Adblock for the Mozilla Firefox browser.
If Flash has been disabled in a web browser then users may be unable to access some Flash-dependent websites, or may experience a degraded user interface.
Using Flash content stores the content of the web page in a binary file and since Flash uses animations, the design of the page is not static. These factors make Flash-based content unsuitable for indexing by search engines.
'Misuse' of Flash software has led to the creation of a new industry term "Flashterbation," where the technology is used in a way that lacks customer focus.