DATABASES AND THE INTERNET - Fundamentals of Database Management Systems - page 370

PC

Web
Server

PC

PC

PC

Database
Server

“The Internet”

PC

PC

Database

PC

F IGURE 14.4
Basic hardware components of the Web
to database connection

''application server,'' Figure 12.4. This is a common arrangement in larger Web
sites. Figure 14.4 shows the hardware components of the Web, including the disks
containing the databases. There are three levels of computers in this arrangement:
the client PCs, the Web server, and the database server. How does all of this connect
together? Let's use an example and talk about this at two levels of detail, first at
a high level and then at a somewhat more detailed level that will introduce some
of the specialized software developed for the Web environment. Remember, this
topic is about database management systems and so our goal in this discussion is to
connect the ultimate user into the database.
Suppose that Good Reading Bookstores has developed a Web site to sell books
to consumers online and that you are about to become one of its customers. Follow
along in Figure 14.4. You sit down at your PC, establish contact with your Internet
Service Provider (ISP) (such as America Online or Microsoft's MSN), and enter the
URL or Web address www.GoodReadingBookstores.com. The browser software in
your PC sends a message to Good Reading's Web server and establishes a ''session''
or connection with it. The Web server sends your browser Good Reading's '' home
page ,'' which your browser displays on your monitor. Suppose you are shopping
for a particular topic. On the home page is a space for you to fill in the book's
name. So, from the information systems point of view, what you are really trying to