Training Guide: Programming in HTML5 with JavaScript and CSS3 Ebook

Lesson 1: Understanding forms CHAPTER 7 313

FIGURE 7-1 he request/response model of the stateless modelT

Web servers now deliver services that go far beyond the original web servers. Now web

servers also handle requests for pages that contain code that will execute at the server and

respond with the results of code execution, as shown in Figure 7-2. Web servers now hold

state (data) between webpage requests, so the developer can connect many pages to form a

web application. Most websites are now set up as web applications containing many web-

pages. The idea of a web server delivering a single page to the web browser and then closing

the connection is outdated. Web servers now implement “keep alive” features for connections

that make the web servers hold the connections to the web browsers open for a period of

time with anticipation of additional page requests from a web browser.

FIGURE 7-2 Web servers maintaining connections and holding state across page requests