The dictionary (www.merriam-webster.com) defines choreography as follows:

• The art of symbolically representing dancing
• The composition and arrangement of dances especially for ballet

Basically, services can be compared to a set of dancers, and a business process to choreography, a direction, or a business process. Each dancer, or a group of dancers, or each service is autonomous in how they all carry out the direction.

So, in service choreography, the composed services interact and cooperate with each other without the presence of a master, director, or controller service composing or combining them.

An easy example of this would be the execution of a combination of cross-departmental or cross-organizational services, where there is no single service controlling the flow.

In the Microsoft world, we achieve service orchestration through the Windows workflow foundation, and orchestration and choreography through the BizTalk server, which also supports Business Process Execution Language (BPEL).