All J2EE application servers must provide containers to house J2EE components. The role of the container is to provide a component with the resources it needs to operate and a runtime within which to execute. While doing this it must also provide a degree of protection (security) to the application host.
Containers provide a number of services for a component. These services include:
Communication with other components
J2EE containers must provide components with certain standard services. Yesterday, you were introduced to some of these services; today, you will explore them in a little more detail and see how they work in conjunction with J2EE components.