Switching Website down modes status to on will block your website visitors from browsing the website pages, and it will only display the same page from your selection (Maintenance or Under construction) will working on your website modifications.

user role(s):

Allows you to open the website for certain users (Editor, Contributor, Author and/or Subscriber) and they can browser the website normally.

Website down mode:

Both modes have the same concept choose a pre-made layout or create your own design (selecting create your own design will allow you to add the page URL you have created within the same WordPress installation).