When developing an EJB, part of the job involves coding the actual business logic. This is no different than coding any regular Java class that you would use in a local application. You'll have public and private methods that are directly related to the application purpose of your bean, but depending on the type of bean you're developing, you may have some additional coding responsibilities.
Session and entity beans require code that enables remote clients to access a subset of your bean functionality. This code is known as the remote interface. They also require that you code life-cycle methods that have to do with how the bean is managed automatically by the EJB container. These methods are part of what is known as the