An application or a service comprises different components that interact with each other. Each component implements a contract defined by the interfaces to achieve a functionality. These components exist in the runtime environment of the system and use the services in the system environment.

An enterprise bean is a server-side component. These beans implement the business logic of an enterprise application and comply with the rules of the EJB architecture. These beans live in an EJB container and the EJB container provides different services to them.

The purpose of EJBs is to provide a framework for the components of the service or an application that may be plugged into a server, thereby extending that server's functionality. EJBs provide an architecture to develop and deploy component-based enterprise applications with a high level of scalability, good performance, and robustness.