: BPMN defines a Business Process Diagram (BPD), which is based on a flowcharting technique tailored for creating graphical models of business process operations. Modelling in BPMN uses set of diagrams with a small set of graphical elements to assist business users, as well as developers, to understand the flow and the process.
: This is an XML based language which is used to define enterprise business processes with web services. The key objective of BPEL is to standardize the format of business process flow definition so that the departments can work together seamlessly using web services. Therefore, BPEL focuses on web service interfaces specifically. There is no standard graphical notation for BPEL. Instead, BPMN is used as a front end tool to capture BPEL process descriptions.
: It is a tool which helps in visualizing architectural blue prints such as activities, individual components of a system, interaction of entities, user interface etc.