SQL Server IaaS Extension is installed by default on Azure virtual machines deployed from SQL Server based images on Azure Market Place. SQL Server IaaS extension manages SQL Server configurations on the VM including SQL server connectivity, storage configuration, automated backup, automated security patching and AKV integration. SQL IaaS Extension automates all these administrative tasks... Read more

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2018/10/25/sql-server-iaas-extension-query-service-for-sql-server-on-azure-vm/