I think the most widely used permission level in SharePoint is the “Contribute” level which allows a user to view, add, update, and delete list items and documents. So this permission level is the ideal for normal users who will be adding and editing documents in SharePoint libraries.
However a user with contribute permissions will also get a totally unexpected privilege, which is the ability to edit pages in SharePoint. This is because the pages are stored in site pages library. In order to stop this, all you need to do is to remove the contribute permissions of the users in the site pages library.
In the site pages library;
- stop permission inheritance
- change the permission level of the relevant users in to “Read” instead of “Contribute.”