WWW Architecture

Week 1, Class 2

The goal for this class is to build a base of background knowledge that will underlie the rest of the course.

In many areas of technology, one gets the impression that the technology as always existed in its current form. But, of course, technology has a history just like any other natural or unnatural phenomenon. So it is for the Internet and the Worldwide Web. During this discussion, we will look first at some of the important developments that have taken- place over the past thirty years that have made the Internet what it is today. After reviewing this chronology, we will look at two of the underlying technologies that support the Internet. The first is ethernet, the original local area network ( LAN) technology and still one of the most prevalent communication systems used to connect computers that are within a few hundred yards of one another. The second is TCP/IP, the software standard that enables computers located around the world to direct messages to one another and to communicate reliably.

After discussing the Internet, we will then turn our attention to the World Wide Web, itself. The discussion begins with a review of its basic client/server architecture, in which a client program running on one computer communicates with a server program running on another to request some particular information or that some service be performed. The Web was built using a client/server architecture in which a Web browser (client) communicates with various Web servers to request pages of information or that a program be run through the server's Common Gateway Interface (CGI). As the Internet/WWW becomes a more general computing and communications infrastructure, this strict client/server relationship is being expanded. One such expansion involves Java. More about these recent developments later in the course, but for now, we will concentrate on the Web's classic client/server design.

The language Web clients and servers speak to one another is called HTTP (HyperText Transfer Protocol). You will not have to learn HTTP in detail, but you will have to construct basic HTTP messages in order to do CGI programming and you should understand its underlying philosophy and its basic form and capabilities.

Topics

Assignment for Next Class