You use Muse to create and update a website. You use Business Catalyst to host it. You must install and use Muse to publish your free sites. Though you can create and edit pages in Business Catalyst, Adobe recommends that Muse users create and edit pages in Muse. Use Business Catalyst only to host the pages. The reason is that if you edit a page in Business Catalyst, your changes are not reflected in Muse. The changes could be overwritten the next time you update the page in Muse and upload it to Business Catalyst.
If you have questions about BC, there’s no reason not to reach out to Karim.Ingrid s.