They are passive, delivering up their information to the reader, but not reaching out and grabbing his or her attention. That is changing as the technology of the Web develops. Today there are three ways to make pages interactive. All these ways depend on extending the capabilities of the Web browser. The simplest way to extend what a Web browser can do is with helper applications.
Most Web browsers support helper applications that sit outside the Web browser.
When the browser hits a file that it does not know how to deal with, it looks in its list of helper applications for a program that knows how to handle that sort of file. It then launches that program to display or 'play' the file. For example, while a browser is downloading and displaying a page, it may come across an MPEG file. MPEG files are one sort of compressed video. Currently no Web browser can turn MPEG files back into video, so they rely on a special helper application called an MPEG viewer to handle this job.