Night Lights refer to lamps kept on at night. In urban areas, night lights have long been an important source of security for home and street life. At home, night lights provide comfort, certain security and convenience. Since ancient times, people burn oil lamps and candles to illuminate their homes and environments. Night lights also enable people to easily remain aware of our home surroundings, and thus bring reassurance and peace of mind. Night lights can serve other purposes too. For instance, some lamps contain a more efficient sensor that simultaneously turns on when natural daylight is fading and automatically turns off when natural daylight returns. This makes it more energy efficient and reduces the need for manual switching of lights in the dark. On the streets, night lights increase visibility and provide a sense of security. The traditional street lamps emit a soft, yellow light with more uniform distribution, illuminating paths of pedestrians and vehicles. Whats more, the motion-detection mechanisms help to ensure an even safer environment. Finally, night lights of modern cities can also be regarded as decorations. Different shapes and colors of street lamps and lights add a touch of warmth and beauty to any street. In conclusion, night lights have a long history of providing security for our homes and streets, while at the same time adding a layer of aesthetic value.