This chapter focused on securing the server against unwanted access, hardening communication between clients and the ConfigMgr server, and configuring remote access to managed computers.
The security of the environment is composed of a few factors, not just properly configuring and granting permissions on the console. Security also comprises preventing server failure, making a backup copy, and checking if the backup is correct and which can be used in the event of a breakdown.
To know more about role-based administration and security here is a very useful link with very interesting materials from which you can start digging for more: https://docs.microsoft.com/en-us/sccm/core/understand/fundamentals-of-role-based-administration.
Adding to these security topics, the next chapter will cover various useful maintenance tasks that are available in the ConfigMgr...