The document discusses Supervisory Control and Data Acquisition (SCADA) systems. SCADA systems are used to monitor and control industrial processes and infrastructure systems. They are comprised of remote terminal units (RTUs), programmable logic controllers (PLCs), human-machine interfaces (HMIs), and communication networks. SCADA systems are used across various industries like manufacturing, water and electricity distribution, buildings, and more. They provide features like real-time and historical trending, alarms, security, and connectivity to devices and databases.