Azure SQL Database is highly available database Platform as a Service that guarantees that your database will be up and running 99.99% of time, without worrying about maintenance and downtimes. This is a fully managed SQL Server Database Engine process hosted in Azure cloud that ensures that your SQL Server database is always upgraded/patched without... Read more

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2018/04/25/azure-sql-database-the-database-engine-that-cannot-die/