Hi Tim,
The desktop entitlements, provisioned an Online Organization and a user for each Desktop license. Each desktop license also allotted for a certain number of credits. You can setup and customize your organization, create web maps and web applications, as well as use the credits towards hosted services, ready to use services, data enrichment, and geoprocessing.
If you have additional questions on the details of this, I would encourage you to contact your Esri Account Manager or Customer Service Representative.
Cheers,
Andrew