Part VI: Access as an Enterprise Platform
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A client/server environment is typically used to service a single company, using a local area net-
work (LAN), or sometimes a wide area network (WAN), where many, many client computers com-
municate with a single server computer. The server computer, quite literally, serves up information
and services. The client computer consumes information provided by the server computer. Of
course, there is a two-way interaction between the client computer and the server computer, such
that client computers can also send information back to server computers.The classic example of client/server computing is the relationship between your computer and a
Web server handling requests for a Web page. Your computer and its Web browser are the client.
The Web server hosting the Web page is the server. You don’t need to know anything about the
Web server, its location, the server software it’s running, or anything else, to use the Web page.
Even if a software add-in is required to display or run a particular Web page, most often the add-in
installation occurs automatically.In this scenario, the Web server is responsible for retrieving the HTML, images, and other
resources required by the Web page, and your Web browser is responsible for rendering the
HTML into the page you see on the screen. The Web browser is also responsible for accepting your
input (mouse clicks, keyboard entry, and so on) and transmitting the input to the Web server.Very often, as in this case, the client is an active participant, and runs executable code on the client
machine. In the case of a Web browser, the code might include JavaScript or VBScript embedded
on the page, ActiveX controls included in the page’s display, or other controls such as Flash Player.From the perspective of browsing a Web page, the Internet is nothing more than a wide-area net-
work connecting computers through the TCP/IP networking protocol. Each computer running a
Web browser is a client connecting to resources provided by Web servers. Most often, very little
data is stored on the client computers, while vast amounts of data may be kept on the Web servers.
The primary purpose of the Web browser application running on the client computers is to pro-
vide an interface to the data provided by the Web servers.In an Access environment, client/server architecture includes environments where an Access data-
base communicates with a server database engine (usually Microsoft SQL Server) running on a
remote server computer, or even running on the same computer as Access.Looking at the Parts of Client/Server
Architecture
A client/server setup is essentially one or more client computers (workstations) running some kind
of application. That client application is connected (usually through a network) to a server com-
puter. The client application’s features — such as input screens and reports — provides an inter-
face to the data managed on the server computer. In many client/server environments, the only
activity that occurs on the client computer is the interaction between the user and the application.