To answer this question, a more basic question to ask would be what is a BizTalk host, since a host must exist before an instance of it can exisit! This distinction may be confusing to BizTalk newcomers because when navigating through the BizTalk Admin Console, hosts and host instances are viewed separately. In mid-90's techno-speak, (READ: about the time-frame where the development of the BizTalk/Commerce Server got its start) the host would have been thought of as a container for related adapter ......