In their swift development over the past decade, modern enterprises in energy, petrochemistry, metallurgy, pharmaceuticals, food processing, transport, logistics and other sectors have crossed the invisible line separating the physical world of machines and mechanisms from the virtual world of computer software. They have essentially evolved into cyber-physical systems, where instructions in machine code control physical objects. These cyber-physical systems are built using modern IT technologies.

https://ics-cert.kaspersky.com/reports/2019/01/17/challenges-of-industrial-cybersecurity/