An Introduction to Java and Program Design - Java Programming: Comprehensive Concepts and Techniques - page 8

Programmers use JSP and JDBC to develop data-driven Web applications.
Experts estimate that 80 percent of the world's computer applications are data-
base applications; therefore, many programmers use Java servlets to develop
database applications for a variety of purposes and deploy them over intranets,
extranets, and the Web. Whether a company's human resource department needs
to deploy an employee benefits application, or a company needs an enterprise-
wide solution for customer service, account management, and inventory control,
a programmer can use Java servlets to develop programs to meet those needs.
Figure 1-6 displays a Web page that uses a servlet to provide functionality.
server
accessed
servlet data
is returned
to browser
FIGURE 1-6
Web Services
Another use of Java is to create Web services. A Web service , sometimes
called an application service, is a program that receives a request for information
from another program over the Web and then returns data to the requesting
program. Web services usually incorporate some combination of programming
and data, but may support user input as well. In a typical Web services scenario,
a business application sends a request to a service at a given URL using a special
Web-based protocol (Figure 1-7). The Web service receives the request, processes