As you know there are so many security measures are taken during every release of SQL Server. This version of SQL Server will be using Managed Service account to run SQL server related services. In other terms earlier versions we used Local system account as service account for all SQL Server related services however in this version we be will using individual local accounts for all SQL server related services. In this case whatever application runs on local system are allowed to access SQL Server. So to overcome this MS team has started using managed service accounts in SQL Server.