In many situations, you find users that access a certain Domino application with the Notes client and at the same time, you will have Domino Connection applications operating on the same database. This is called a "hybrid" application setup.

You can manipulate data with Domino Connection in a way that would not be possible using the Notes client software. You can, for example write documents into a database that would not pass the form validation phase (because you can omit field validation if you like).