User Permisions

User permissions are not clear in this part.

What is the exact function?

Thank you.

// clock
// home
// Update
// preview

The permissions are for pages (as in pages table in Xibo database).

Clock - there is a clock page /clock, that would be permissions to see that page.
Home - permissions to the homepage set for that user
Update - there is a page /update, it is not accessible by any menu item, you’re redirected to this page if the CMS needs an update (ie say you upgraded your cms and after first login you might be redirected to /update page if CMS needs to run some upgrading steps).
Preview - CMS preview for layout/campaign. you can notice that when you are previewing a layout, you are redirected to /layout/preview/{layoutId} page.