Chapter 1. What Is HTTP?

At a technical level, the World Wide Web is a difficult thing to comprehend, mainly because it is an intangible object. Most people have a general idea of what it is, at least from their perspective, but their interest quickly fades beyond that basic understanding. Despite this, the Web is something that is easily defined, and that definition will help explain the important role of HTTP.

If you were to create a medium of communication like the Web, assuming an existing network of computers such as the Internet, there are three major questions you would need to provide answers to in order to create this medium and make it useful to potential users:

• How will users of this system locate content, or how will the providers of the content identify themselves?

• How will users of this system retrieve content once located, or how will the providers of the content send it?

• In what format will the content be submitted so that it can be interpreted consistently by all users?

The three answers to these questions in the case of the Web are Universal Resource Identifiers (URIs), Hypertext Transfer Protocol (HTTP), and Hypertext Markup Language (HTML), respectively.

Of these three technologies, the focus of many Web developers has been in the knowledge of the markup language HTML. When the intent is to only create static content such as a personal home page, this knowledge can actually suffice. However, when providing dynamic content, and especially when creating a Web application, understanding the answer to the second question becomes crucial. The reason is that in these cases the data or information is more important than the way the information is formatted.

Take, for example, the Web site of a bank. As a user of this site, would you be more interested in knowing your savings account balance or whether your savings account balance was shown in an aesthetically pleasing manner? In order to develop useful and successful Web sites, it is important to focus on what your users are more interested in, and in most cases, that is the content.

Because this book focuses on content and the delivery of that content, it provides a good introduction to professional Web development from this perspective.