TCP/IP is a lower-level protocol whose job is to get data reliably from one computer to another. HTTP is a higher-level protocol, which is used to move requests from a client to a Web Server and responses from a Web Server to a client.
It stands for the Model-View-Controller architecture.
An MVC design subdivides the task of creating an interactive system into logical subsystems. By grouping these functions logically, you get an easier design to understand and modify.
Session Beans can be used for the Controller layer, and Entity Beans can be used for the Model.