Hi Marry
Not sure if you are looking for this information now but for others who are looking for same information, Pl check below links to understand message flow context,
http://www.erpgenie.com/sap/mysap/crm/flowcontext.htm
https://help.sap.com/saphelp_crm60/helpdata/en/fd/3d3be7dd7b11d3a6ee0060087832f8/content.htm