What if I want to use Museums Sites only as a collection management system?

Of course you can use Museums Sites as a Collection Management System only, without creating a full website (as you may already have one) or even without making your website public. The option to create a website will always be there for you, just in case you change your mind.

You may even use Museums Sites as a collection management system and export its content to a separate website, using the embedded API. Although Museums Sites offers many features, you don't have to use them all - it's completely up to you to decide what you want Museums Sites to do for you and your organisation.