Azure SQL Database is one of two ways organizations can leverage SQL Server in the Azure cloud. The other is SQL Server on Azure Virtual Machines (VMs), which uses an Infrastructure-as-a-Service (IaaS) model to host an instance of SQL Server.
Database-as-a-Service (DBaaS) is a relatively new entry in the field of cloud-based deployment models, but it’s rapidly gaining in popularity.
Azure is Microsoft’s cloud computing platform, providing a variety of service that can be used without purchasing or provisioning hardware. Azure enables the rapid development of solutions and provides the resources to accomplish tasks that may not be feasible in an on-premise environment.