In this section of the course, you learned that even though Linux is a relatively secure operating system that doesn't mean you can let your guard down. End users and system administrators alike play an important role in security. Some of those people may not have the proper training. Some are not security focused and everybody makes mistakes from time to time. Sometimes those mistakes can have security implications. We also talked about how security is an ongoing process. Once systems are put into service, they change through use. Accounts need to be created or deleted, logs need to be monitored, et cetera. Security is a consideration for the entire lifespan of a system. You also learned about some of the security features of Linux, including that it's open source. It's not as easy or popular of a target than some other operating systems are currently. You also learned about the security advantages of using packages provided by popular Linux distributions. We even talked about the advantages of Linux being a multi-user operating system. Finally, we talked about several security principles and guidelines. Some of these included the principle of least privilege using encryption over the network as well as on disc, how to handle shared accounts and how using multi-factor authentication mechanisms enhance security. You learned about the built-in firewall capabilities of Linux. Finally, we talked about the importance of reviewing, monitoring, and securing logs on your systems.