These are domains that are preset by Maglr. Allowing you to use maglr.com/maglr.nl/digitaal-magazine.nl as a domain, this is used when you don't have a custom domain for yourself and you won't mind the domain being related to Maglr. Still enabling you to create a name for the domain along with a filter to show certain publications.
These are for when you have a host/provider that has given you a custom named domain that you have chosen. This allows you to then host and allow your publications for viewing on a custom domain that may be connected to your company. This options still allows you to select a filter to show specific publications on that domain.