Christmas lights are clear, single-color and multi-color strands of lights used to decorate Christmas trees as well as the inside and outside of houses. Christmas lights come in various sizes and shapes and may be designed specifically for indoor or outdoor use.
The use of Christmas lights began in the 17th century when wealthy Germans glued or pinned small candles to their Christmas trees. In 1882 in New York, Edward H. Johnson, an associate of Thomas Edison, used the first electric lights on a Christmas tree. Because electric lights were expensive, most people during that time continued to use candles to light their trees.