The term safety razor was first used in 1880 and described a basic razor with a handle attached to a head where a removable blade may be placed. The edge was then protected by a comb patterned on the head which is used to protect the skin. In the more modern-day produced safety razors, the comb is now more commonly replaced by a safety bar. There are two types of safety razors, the single edged and the double-edged. The single-edged razor is essentially a 4 cm long segment of a straight razor. The double-edged safety razor is a razor with a slant bar that can be used on both sides, with two open edges. The blade on the double-edged safety razor is slightly curved to allow for a smoother and cleaner shave.
In 1901, the American inventor King Camp Gillette, with the assistance of William Nickerson, patternted a new variation of safety razor with disposable blades. Gillette realized that a profit could be made by selling an inexpensive razor with disposable blades. This has been called the Razor and blades business model, and has become a very common practice for a wide variety of products. "Razor". Wikipedia. Retrieved 2015-12-01.