Over the years, Apple has gone to great lengths to make OS X strong by hardening its user security. Hardening means strengthening a component in a system to make it more secure. User accounts can be hardened in OS X by limiting the resources that users can access. You can accomplish this two ways: by using the built-in GUI tools, or by using the command line. In this chapter, we will go deeper into securing the Mac by focusing first on restricting user access and then on more advanced command-line security that can be used to harden user accounts.