What is the service provided by IoT hub?

Services that are provides by IoT service providers 

• it. Provides secure device-to-cloud and cloud-to-device reverse communication options
• It provides a data warehouse to  store device metadata that can be later searched by using database search queries
• It provides Queryable storage of per-device state information as well as meta-data.
•  It provides device libraries for the platforms which are being used by most for easy device connectivity