Web application development requires a basic understanding of networking and the World Wide Web. In this section, we discuss the Hypertext Transfer Protocol (HTTP) and what occurs behind the scenes when a user requests a web page in a browser. HTTP specifies a set of methods and headers that allow clients and servers to interact and exchange information in a uniform and reliable manner.
In its simplest form, a web page is nothing more than an XHTML document—a plain text file containing markup (i.e., tags) that describe to a web browser how to display and format the document’s information. For example, the XHTML markup
<title> My Web Page</title>
indicates that the browser should display the text between the <title> ...