Proximity sensors detect nearby objects without making physical contact. There are several types including inductive, capacitive, ultrasonic, and optical proximity sensors. Proximity sensors are commonly used in smartphones to disable accidental touchscreen inputs when objects like ears are near the screen during calls. They work by sensing objects close to the speaker and ignoring any touch events that are detected. The global market for proximity sensors is growing as they are used in applications like machinery, automatic doors, elevators, and the automotive and building industries.