Custom Metadata Types: Relationship Field Updates, Loader Enhancements, Management of Deleted Metadata

Build better apps than ever before with custom metadata types which let you base your apps on types of metadata rather than just data. Zoom your view on related records with relationship fields, power through record updates, easily delete or undelete relationship fields, and get the full scoop on referenced custom objects. This feature is available in both Lightning Experience and Salesforce Classic.
Available in: Professional, Enterprise, Performance, Unlimited, Developer, and Database.com Editions

Professional Edition orgs can create, edit, and delete custom metadata records only from types in installed packages.