is a device which follows the movement of the sun as it rotates from the east to the west every day. Trackers are used to keep payloads oriented directly towards the sun as it moves throughout the day. Payloads usually are solar panels, parabolic troughs, fresnel reflectors, lenses or the mirrors of a heliostat.
Trackers increases the amount of solar energy which is received by the solar energy panels and improves the energy output of the heat/electricity which is generated. Trackers can increase the output of solar panels by 20-30%.