Hiding a page involves setting a page so that it is effectively invisible on your site.
A hidden page is published - however, the only way a hidden page can be accessed is via the page's URL.
To hide a page, first go to 'Pages' on the navigation bar.
Using the 'Site Structure' sidebar on the LHS, choose the location in which the page is located in and select the page.
Under the 'Basic details' of the page, there is a toggle titled 'Hidden', which allows you to switch the page between hidden and unhidden.
Click on the toggle, and select 'Save' at the bottom of the page.
Watch the video below for a short tutorial on hiding Pages.