The cyber kill chain outlines the typical steps an attacker takes to compromise an organization's systems, including reconnaissance, weaponization, delivery, exploitation, installation, command and control, and actions on objectives. It is used to understand how attackers plan and execute attacks to bypass perimeter defenses. The chain includes 7 steps: 1) reconnaissance, 2) weaponization, 3) delivery, 4) exploitation, 5) installation, 6) command and control, and 7) actions on objectives.