The standards for an impressive Internet presentation have changed substantially since Tim Berners-Lee created the first web pages. Internet sites increasingly remind the surfer of interactive desktop applications rather than printed material. AJAX is a technology based on JavaScript that adds convenience, with pull-down menus, sortable tables, and interactive input pages. The main improvement is the absence of delays typically experienced while pages reloaded.

Long Way

Before rendering a website, the browser and web server go through a number of steps (Figure 1):

• The browser sends a page request to a web server.
• The server processes the request and serves up the HTML text and images. This might take a couple of seconds if the load is heavy. The network transmission speed decides how fast the content is delivered. The required time is still noticeable on fast intranets, however.
• Finally, the browser reads the response and displays the page. The same sequence is repeated for each image before the browser can render the final version of the page.

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