Resources are based on resource types and they are available from resource providers. There are numerous providers available in Azure and they provide the necessary resource types needed by users to create their instances. For example, the Microsoft.Compute resource provider provides virtual machines resource types. Using virtual machines resource types, instances of virtual machine can be created.
Resource providers are required to be registered with Azure subscriptions. Resource types will not be available in a subscription if resource providers are not registered. To get a list of providers that are available, the ones that are registered and the one's not registered and to register non-registered providers or vice-versa, this dashboard can be used:
