A propulsion system refers to the machinery and mechanisms that generate thrust to move a vehicle, such as a ship, through water. In maritime contexts, this typically includes engines, propellers, shafts, and related components that convert energy (usually from fuel) into motion. The system's design can vary widely, from traditional diesel engines to advanced electric or hybrid systems. In cybersecurity, propulsion systems are considered critical infrastructure, as their compromise could disrupt transportation or lead to safety hazards. Protecting the digital controls and networks that manage these systems is essential to prevent unauthorized access or sabotage.