SCADA (supervisory control and data acquisition) refers to industrial control systems which consist of computer systems that monitor and control various electrical networks.
A SCADA system normally consist of
A human–machine interface (HMI): It is a device which presents data to a human operator, and this helps human operator to operate and monitor various control systems.
A supervisory computer system which gathers data and then process it for sending control commends to the system.
Remote terminal units (RTUs) consist of sensors which help to convert incoming single to digital data which is used by supervisory system for controlling.
Programmable logic controller (PLCs) used for various logical programming to be done for specific action through solenoid, relay, circuit breaker, etc.
Communication infrastructure for connecting all the systems with each other
Eg: SCADA systems are often used in power plants and manufacturing units for all its control system requirement.