Since ancient times, mariners have depended on light to warn them of dangerous shores and to guide them safely to their ports. In the beginning, navigational aid was as simple as a fire. They were kept burning at selected locations where mariners could see them from a long distance.
Like other things in life, mankind keeps trying to make things better. Consequently, lights to guide mariners have greatly improved over the years. Navigational aid has gone from burning a fire to hanging a lighted lantern on a post to burning candles in a window. Towering lighthouses were built and fitted with lamps and reflectors, and then lighthouses were later fitted with oil lamps and sophisticated and complex Fresnel lenses. Then, electricity came to lighthouses and the oil lamps became obsolete due to the electric light bulb. Many lighthouses still use the Fresnel lens with the electric light bulb. But, some lighthouses have had their bulb and lens replaced by a beacon type of light similar to one at an airport.
Surely, the modern day mariner without a Global Positioning System (GPS) appreciates and enjoys using any of the current navigational lights.