I'm finding acronomes such as 'SSIS', 'SSDT', etc etc a little confusing as to how they related to SQL Server. It seems to me that SQL Server implements the T-SQL language, and that a package such as 'SSIS' is a 3rd party 'wrapper' over the T-SQL language, and effectively a plug-in to SQL Server. Is this correct?

This blog post ([here](http://www.jamesserra.com/archive/2011/08/when-to-use-t-sql-or-ssis-for-etl/)) mentions the benefits of SSIS vs T-SQL (which is why I assume that SSIS is a wrapper of T-SQL). Also, I can see that jobs created as SSIS packages can be found under SQL Server Agent in SSMS.