The HART Protocol, or Highway Addressable Remote Transducer Protocol, is a communication technology used in industrial automation. It enables two-way digital communication between field devices, such as sensors and actuators, and control systems. HART operates over existing 4-20 mA analog signals, allowing for easy integration with legacy systems. This protocol supports various device types and provides access to device diagnostics and configuration data. It enhances the functionality of traditional analog devices by allowing users to monitor performance and make adjustments remotely, improving efficiency and reducing downtime in processes across industries like oil and gas and manufacturing.