My understanding is: Edit: I found a couple of Dell articles that provide further info: 
I have purchased a new Dell XPS 8950. I also purchased Dell migrate (part of Data assistant I believe). to be installed on the XPS 8950 I wish to migrate from the current Dell XPS 8930 to the new Dell XPS 8950. Which has not yet been delivered. Does the migrate process keep  all the original data on the older computer or does it delete that data after transfer. Also, does the migration include the registry files for the programs migrated or do I have to install all of those into the new computer?  If so, why migrate.....I can just reinstall the programs. Man I hate this moving this software to  the new computer by copy paste or new install.      
Dell Migrate