The monokini was designed by Rudi Gernreich in 1964, consisting of only a brief, close-fitting bottom and two thin straps; it was the first women's topless swimsuit. His revolutionary and controversial design included a bottom that "extended from the midriff to the upper thigh" and was "held up by shoestring laces that make a halter around the neck." Some credit Gernreich's design with initiating, or describe it as a symbol of, the sexual revolution.

A bikini is a two-piece swimsuit primarily worn by girls and women that features one piece on top that covers the breasts, and a second piece on the bottom: the front covering the pelvis but usually exposing the navel, and the back generally covering the intergluteal cleft and a little, some, or all of the buttocks. The size of the top and bottom can vary, from bikinis that offer full coverage of the breasts, pelvis, and buttocks, to more revealing designs with a thong or G-string bottom that covers only the mons pubis, but exposes the buttocks, and a top that covers only the areolae. Bikini bottoms covering about half the buttocks may be described as "Brazilian-cut".