A yard light is an independently powered outdoor light that illuminates relatively small outdoor areas, such as driveways and yards. As the name implies, yard lights initially were developed to increase nighttime visibility in the front and back yards of private homes, but they have come to serve a wider purpose through use in public places and on farms, ranches and any other outdoor sites where increased nighttime visibility is desired. There are various sources of power for yard lights, including electrical, battery, natural gas and solar energy.
Both battery- and natural gas-powered yard lights work fairly efficiently without reliance on an external power source, such as an electrical outlet, solar yard lights have come to prominence because of their energy efficiency and convenience. Over the course of the day, a solar yard light takes in the sun's rays through a solar panel in order to power its energy cells for when nighttime comes. The owner of a solar yard light does not need to be concerned with monitoring the device periodically to make sure that the battery or natural gas supply remains sufficient. As a result, the solar-powered light also functions well in largely unmonitored outdoor areas, because it requires almost no maintenance.
A common feature of contemporary yard lights is motion detection. Many homeowners install motion-sensitive yard lights around their driveway in order to illuminate it when someone enters the light's area of detection, which ideally should cover any area in which the homeowner is concerned about visibility. When the motion sensor is triggered, the yard light will light up the area and render anyone within its range visible. This function serves the dual purposes of providing light for guests as they approach the house and of deterring any undesired visitors, such as robbers or trespassers.