Cotton candy (also known as fairy floss in Australia, candy floss in South Africa, the UK and New Zealand) is a form of spun sugar. According to the New York Times, the confection "is 100 percent sugar, with dashes of flavoring and food coloring."
Made by heating and liquefying sugar and spinning it out through minute holes, where it re-solidifies in minutely thin strands of "sugar glass," the final cotton candy contains mostly air, with a typical serving weighing approximately 1 ounce or 30 grams. Often served at fairs, circuses, carnivals, and Japanese festivals, cotton candy is sold on a stick or in a plastic bag. Food coloring can be used to change the natural white color, and numerous flavorings are available to change the taste.
Cotton candy was first made in Europe in the 18th century. At that time, spun sugar was expensive. The average person could not afford it. Machines to spin the sugar were invented in 1897 by dentist William Morrison and confectioner John C. Wharton. They introduced it at the World's Fair in 1904, under the name Fairy Floss. It was very successful. They sold 68,655 boxes at 25 cents each box (equivalent to US$6 per box today).
Source(s): wikipedia | nationaldaycalendar