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How Web Animation Works


In the early '90s, the Internet really started to take off in popularity, and the number of Web sites skyrocketed. There was suddenly a wide variety of people producing Web pages, and they had all sorts of multimedia content they wanted to be able to include. Rather than trying to change browsers to recognize and display these many different forms of content, Web innovators launched the idea of browser plug-ins.

Plug-ins are programs that work with your browser to read and play a certain type of file. They are relatively small pieces of software, so it doesn't take users forever to download them off the Internet. They are specifically designed to work with a particular type of file, so they can accomplish a lot of things that a basic browser can't.


Streaming video generally uses a plug-in approach that lets you view video content on the web. Web video can include sound and much more elaborate animation.

These days, Web designers can use dHTML scripts to detect whether or not you have a particular plug-in. If you don't have it, your browser will display a message that tells you how to download the plug-in. This varies from application to application, but it often takes a good while to go through the entire process, which is a definite disadvantage of handling animation this way. If you already have the plug-in, most browsers will start playing the movie as soon as enough of the file has started downloading.

Different plug-ins work in different ways. Video player applications such as QuickTime and Media Player show a sequence of still images, just like an animated GIF or a movie on video, but they are able to transmit the images faster by compressing and streaming them. Compressing is the process of simplifying the information that makes up an image so that its file size decreases. Streaming simply means that the player begins displaying the content before the entire file has downloaded.

Even with these capabilities, this sort of movie file takes a long time to download or has poor quality if you have a slow connection.

Flash and Shockwave

By far the most common plug-ins for dealing with animation are Flash and Shockwave, both from Macromedia. These are vector-based 2-D animation viewers. The following sections discuss Flash and Shockwave in detail.


A Flash animation from our boomerang article.

A Flash animation from our boomerang article.