SCADA systems are used to monitor and control geographically dispersed assets, like pipelines, power grids, and water distribution systems. SCADA systems connect to physical equipment like sensors and valves and gather data which is sent to centralized data acquisition systems for monitoring and processing. Key components of SCADA systems include remote terminal units for data collection, programmable logic controllers, telemetry systems for data transfer, and human-machine interfaces for display of information. SCADA systems provide advantages like reduced costs and increased efficiency for monitoring large remote assets.