question

Data Source and Data Source Views are not used by SSIS Packages. However you can create Data Sources and Data Source Views on the SSIS Project Level. Then those objects simplifies development of multiply packages. As you can create a Connection Managers in a Package from a Data Source in the project and once you have such connection manager in place and also have a data source defined, then Sources/Destinations and other objects in SSIS package can benefit from this. Like eg. OLE DB Source can use a named query from the defined Data Source. In this case when you edit the named query in the Data Source, the query will be automatically updated in all SSIS packages referencing it. (but only when you open the package in design mode - I mean connections and other objects in SSIS packages are updated from the project level Data Sources and Data Source Views only after opening in designer, one by one). If you want more info, don't hesitate to ask.