A magnetic sensor is a device that detects changes in magnetic fields. It can measure the strength, direction, or presence of magnetic fields, making it useful in various applications. Common types of magnetic sensors include Hall effect sensors, magnetoresistive sensors, and fluxgate sensors. These sensors are often used in smartphones, automotive systems, and industrial equipment. Magnetic sensors play a crucial role in navigation and positioning systems. For example, they help in determining the orientation of devices, such as compasses in smartphones. Additionally, they are used in electric motors to monitor performance and improve efficiency, contributing to advancements in technology.