Sunscreen is used to protect people from the harmful ultraviolet rays from the sun. Suntan lotion is used to make relatively pale people darker in skin color. However, these two terms are used interchangeably because many people have the misconception that suntan lotion protects skin from ultraviolet rays just because the skin no longer burns. Only products with the label SPF, which stands for sun protection factor, actually protect skin against ultraviolet rays.
While the ancient Greeks used olive oil as a sort of suntan lotion, it was not completely effective.
In 1936, Eugene Schueller, the founder of L'Oreal, invented the first formula for suntan lotion. Not many people knew about it, however, because public interest was low.
Public interest in suntan lotion rose during World War II, when many soldiers were in service along the South Pacific and their skin was constantly being burned by long exposure to the sun.
In 1944, Benjamin Greene invented a red-hued ointment he originally called "red vet pet," which is used as protection against burning from long exposure to the sun's rays. He tested this formula on his head, then sold it around Miami under the company name Coppertone.
Research has elaborated on the effect of the sun's harmful ultraviolet rays on human skin. There are also many brands of assorted sunscreen and suntan lotion as well.