Introduced in SQL Server 2012 and focusing on Self Service and Corporate Business Intelligence. SQL Server Web Edition is a low-TCO option for Web hosting. It differs from Enterprise edition in that it supports fewer active instances (number of nodes in a cluster) and does not include some high-availability functions such as hot-add memory (allowing the memory to be added while the server is still running), and parallel indexes. SQL Server Standard edition includes the core database engine, along with the stand-alone services. It can manage databases as large as 524 petabytes and address 12 terabytes of memory and supports 640 logical processors (CPU cores). SQL Server Enterprise Edition includes both the core database engine and add-on services, with a range of tools for creating and managing a SQL Server cluster.
We discuss Mainstream Edition in very short: Enterprise Mainly, SQL Server is available in three types of the edition, which is Mainstream Edition, Specialized Editon, and Discontinued edition.