Just because you don&#x27;t have more than one &quot;person&quot; user on a system doesn&#x27;t mean you don&#x27;t have multiple users. The UNIX security model is based on user separation, and has been used in many server environments to define boundaries between different privileges on the system.<p>Security wouldn&#x27;t be possible without this. You can also think of cgroups&#x2F;lxc&#x2F;docker as a direct extension of this.