What is Webcasting?
Webcasting is any technology that enables automatic delivery of information from Web sites on the Internet. For example, you might make use of webcasting to receive a weather report update every 10 minutes. An example of a technology that enables webcasting is the Channel Definition Format (CDF) technology included with Microsoft Internet Explorer versions 4.0 and later.
Webcasting in Internet Explorer 4 can be divided into three categories:
Basic webcasting: Any existing Web site can be enabled for webcasting without modification to the site format and content. Internet Explorer can be scheduled to “crawl” the site at scheduled time intervals, check for new or updated content, and notify the user of this content or download it for offline browsing. This process is called “subscribing” to the Web site.
Managed webcasting: An ordinary Web site is turned into an Active Channel Web site when you create a CDF file for the site by using any text editor. The author of the site can optimize and personalize the site and control how it is webcast to users. This is essentially a form of “smart pull” technology.
- “True” webcasting: Uses Internet Protocol (IP) multicasting to push content to the browsers of users who belong to a multicast group. This is an example of true push technology.
The term “webcasting” is sometimes used to refer to the broadcasting of radio programs over the Internet.