Security has always been important to protect physical, information and financial assets. But before digitalization, the majority of threats were visible and took place at a clear geographical location. With the mass integration of cyber physical systems, we are now facing a new set of security risks, and cyber security has become a global preoccupation. This presentation outlines why not every cyber attack is equal and the difference between IT and OT in the protection of critical infrastructure systems such as electricity networks, transportation, healthcare, water supply, etc.