In SQL Server 2016 SP1 features that used to only be available in the enterprise-edition are also available in the other editions, even in the express-edition!
Think of features as datacompression, partitioning and ‘always-encrypted’.
Unfortunately online indexrebuilds will still be an enterprise-only feature. Nevertheless the new features in the non-enterprise-editions can save companies a lot of money!
Be careful when you remove SP1 without thorough research when you are using the new extra features, this may lead to serious problems and corruption.
See also https://technet.microsoft.com/nl-nl/windows/cc645993(v=sql.90) and https://www.microsoft.com/en-us/sql-server/sql-server-editions