The Java EE 6 Tutorial, Volume I

Java EE Server Communications

Figure 1–2 shows the various elements that can make up the client tier. The client communicates with the business tier running on the Java EE server either directly or, as in the case of a client running in a browser, by going through web pages or servlets running in the web tier.

Figure 1–2 Server Communication

Diagram of client-server communication. Application clients
access the business tier directly. Browsers, web pages, and applets access
the web tier.