Figure 2-1, which we'll reference as we progress through this chapter, depicts the BizTalk architecture.
The receive ports on the left side consist of adapters, the End Point Manager (EPM), and receive pipelines, and are responsible for bringing messages into BizTalk from a source system and storing them in the BizTalk MessageBox.
Orchestrations in the center are an optional feature of BizTalk in that you can choose to leverage orchestrations to process messages, as required. Messages that are processed by orchestrations are retrieved from the BizTalk MessageBox, and any messages sent from an orchestration are stored in the BizTalk MessageBox.
The send ports on the right side consist of adapters, the End Point Manager (EPM), and send pipelines, and are responsible for collecting outbound messages from the BizTalk MessageBox and transmitting them to the destination system.
The following sections walk you through all the key components, to deepen your understanding of how all the architectural pieces work together.