by default .. all apps are assigned to "default" scope.
If you choose a SCOPE.. you then define a powershell detection script to identify membership in that scope.. and an order of evlauation.
Then Allow a defined scope to be selected for each application/update.. with different settings. If you define a scope for a piece of software.. it gets added to sccm/wsus with the Scope added to the application name so it can be identified as being applicable to that scope. (so you could end up with multiple sccm application installs for each)