Oracle DB administrator-specific security features
I do not know if there is a SQL Server equivalent but they are probably talking about Oracle Database Vault. It allows administrators to take care of operations on the database without having access to the data. Now if your organization doesn't make the distinction between a role where DBAs handle operations functions vs DBAs that have access to data (to run DDL scripts, DML, etc) then this isn't much help. But it can help limit exposure in those situations where only a few people need to access data but where many help keep up with database operations.