Please check out SQLShack.com for three articles on SSIS. I wrote them based on using the SSIS Catalog and Project Parameters created in SQL Server 2012 and improved on in the next 2 releases. Project parameters are a big deal in SSIS for changing values when executing a package or packages. The parameters are at the project level so you only have to change them once to effect multiple packages.
I use a simple example like changing the database name and server (instance) name for the Project level Connection Manage WHICH is another big change for SSIS. Starting in 2012, you can share connections among packages in a project. Enjoy!!!