Note Java classes can be deployed in a jar file. Appendix A details how to compile a class that uses other classes in a jar file. Appendix B shows how to run a Java class in a jar file. Appendix C provides instructions on the jar tool, a program that comes with the JDK to package your Java classes and related resources. A class that uses another class is said to "depend on" the latter. A UML diagram that depicts this dependency is shown in Figure 4.8.