I have been writing about business processes for some time now. This is because I am working on an SOA initiative that recognizes the business process layer and wants to perform top-down analysis. A colleague recently asked me about all these BPXX acronyms and what they meant. Let me try to explain them with analogy to UML and Java:

BPM

Business Process Management (BPM) is a field of knowledge encompassing tools and techniques to design and analyze business processes.

BPMN

I have discussed Business Process Modeling Notation (BPMN) in more details here. In a nut shell, BPMN is very similar to UML. It's a pictorial representation of a business process just like UML is a pictorial representation of software. BPMN notation defines pictures (notations) to show a process, task, sub-process, events, message flows and more. What shape in BPMN means what is described in BPMN specification. Like UML, BPMN specification is also owned by OMG.

BPEL

BPEL is to BPMN what Java is to UML. In other words, BPEL is an xml based language that defines runtime behavior of the business process. Like Java code has to be written with correct syntax, BPEL must also be written with correct syntax and like Java, BPEL process can be deployed to a runtime server. Like you can generate Java from UML, you can generate BPEL from BPMN. However, not all tools provide this functionality. And similar to UML, BPMN doesn't have to be deployed as BPEL.

WS-BPEL

This is analogous to various specifications around Java technology. Like JSR 154 is a pdf file containing servlet 2.4 specification, WS-BPEL is a pdf file containing BPEL specification. Like a servlet must conform to JSR 154 specification, a BPEL process conforms to WS-BPEL specification.

BPEL4WS

IBM developed this service orchestration standard and later submitted to OASIS. BPEL4WS has been renamed to WS-BPEL.