HMI (Human-Machine Interface) and SCADA (Supervisory Control and Data Acquisition) are two related but distinct concepts commonly used in industrial automation and control systems:

1. HMI (Human-Machine Interface): An HMI is a user interface or dashboard that allows operators to interact with machines or systems. It provides a graphical representation of the system's status and allows users to monitor processes, control equipment, and receive feedback. HMIs typically include elements such as buttons, switches, gauges, alarms, and trend displays, all presented in an intuitive format for operators to understand and manage industrial processes effectively.

2. SCADA (Supervisory Control and Data Acquisition): SCADA refers to a system used to monitor and control industrial processes remotely. It comprises hardware and software components that collect data from sensors and instruments in real-time, allowing operators to monitor the processes and make decisions accordingly. SCADA systems often include features such as data acquisition, networked communication, graphical visualization, alarm notification, and historical data logging. They are commonly used in industries such as manufacturing, power generation, water treatment, oil and gas, and transportation.

In summary, while HMI focuses on the user interface aspect of industrial control systems, SCADA encompasses a broader range of functions, including data acquisition, control, and monitoring of industrial processes from a centralized location. Often, HMIs are a component within a larger SCADA system, providing the interface through which operators interact with and control the industrial processes being monitored.