The document presents a comparison between Oracle SOA Suite 11g Mediator and Oracle Service Bus (OSB), detailing their functionalities and appropriate usage contexts. It outlines the evolution from Oracle SOA Suite 10g to 11g, introducing a common service infrastructure and the roles of various components like BPEL and OSB. Ultimately, it suggests that the choice between Mediator and OSB should depend on specific project needs, with recommendations for using both in complex environments.