apparmor.d is an AppArmor policy to confine all user space processes on the system. This allows users to enforce a strong security model and follow the principle of least privilege. An AppArmor policy for the init and systemd is loaded, which then applies to all other processes. Specific policies for many system services/applications are also enforced.
Still in development, still unsupported by Kicksecure. Not yet available for users.