What is the difference between SQL Data Services and Windows Azure Storage Service?
SDS is a rich, scalable distributed relational database service in the cloud that is used for storing and querying structured & unstructured data. Windows Azure Storage Service is scalable file storage in the cloud. If you are developing a application that requires a highly scale-out file system blob storage then Windows Azure Storage Service will fulfill your need. On the other hand, if your application requires support for database queries then SDS will fulfill your need.