Hall sensors are used to measure the magnetic field strength. However, in most applications it is not necessary to know the absolute value of the magnetic field strength, but the spatial dependency of the magnetic field strength is used to determine the position of the sensor relative to the magnet.
Hall switches are used as “magnetical switches”. Depending on the distance between magnet and sensor the output signal switches between high and low.
Linear distance Hall-sensors provide an analog or digital output signal as a function of the distance of the magnet relative to the sensor.
Direct angle Hall-sensors provide an analog or digital output signal as a function of the rotating angle of the magnet relative to the sensor.