who can tell me the jbpm work theory? i want to know it very much, now i only write some simple demo to access this process. but i don't know it is how to run, what is work theory, when a application start, what do it,

i don;t know it is right or not, i think when a application run, the process engine will load all process definied, when a request come, it will use a session to find this defined process,and instance this process, for a process, it will execute by this request. for example, i can use the value of request give...

if my thought is wrong, please correct me.,or tell me the theory. thank you very very much..