The Corporate License entitles an organization (corporation, company, enterprise...) to receive one copy of the software and to install it on multiple machines within one organization at single location.
The Corporate Premium License is extended version of Corporate License having support of Office 365 and Exchange online. It has dedicated 24*7 technical support.
The Technician License is meant for Data Recovery Service provider companies. It can be used to recover your client's data at their premise/locations/sites.