CPS stands for cyber-physical systems: environments where software, physical equipment, analog signals, and human operators work together to run real-world processes. Examples include industrial control systems, building automation, sensors, robotics, and connected medical or utility devices.
CPS matters in cyber security because a compromise is not limited to data theft. An attacker can change commands, disrupt timing, falsify sensor readings, or block operator visibility, causing downtime, unsafe behavior, or mission failure. Defenders protect CPS by segmenting networks, limiting remote access, authenticating privileged actions, monitoring process behavior, and validating that commands match expected physical conditions. In practice, CPS security focuses on both IT controls and the safety and reliability of the underlying operation.