The Java EE 6 Tutorial, Volume I

Business Components

Business code, which is logic that solves or meets the needs of a particular business domain such as banking, retail, or finance, is handled by enterprise beans running in either the business tier or the web tier. Figure 1–4 shows how an enterprise bean receives data from client programs, processes it (if necessary), and sends it to the enterprise information system tier for storage. An enterprise bean also retrieves data from storage, processes it (if necessary), and sends it back to the client program.

Figure 1–4 Business and EIS Tiers

Diagram of client-server communication showing detail
of entities, session beans, and message-driven beans in the business tier.