BP components, or modeling elements, include activities, branching activities (decision points), intermediate activities, and links, as well as the business rules that define the logic of how data is transformed and moved. You can create sub-processes that can then be incorporated into a main BP.
The modeling elements you add from the Business Process Designer are standard BPEL elements, and are described in detail in Business Process Activities.
By default, the Start and End activities appear on the blank Business Process Designer as soon as you create a BP. There is only one starting point for any BP model. There can be multiple end points.