The module works in the following way:
Data is transferred from the source Sitecore installation to the target installation via a web service. The web service is supplied with a special service package which is installed on the source installation. This service provides a kind of portal for data transfer.
A Migration Wizard is installed on the target Sitecore installation. This Wizard guides you through the data transfer process.
Both installations should work simultaneously as two separate IIS sites – the Wizard on the target installation for process control and the Service on the source installation for data exporting.
Such architecture makes the module compliant with a wide range of previous Sitecore releases and independent of the database types used.