A bikini or two piece is a women's swimsuit with two parts, one covering the breasts (optionally in the case of the monokini), the other the groin (and optionally the buttocks), leaving an uncovered area between the two (optionally in the case of the Tankini).
It is often worn in hot weather or while swimming.
The bikini, which shocked when it appeared on French beaches in 1947, dates back to antiquity, in Çatalhöyük and the Greco-Roman world. The modern bikini was invented by French engineer Louis Réard in 1946. He named it after Bikini Atoll in the Pacific, the site of the Operation Crossroads nuclear weapon test on July 1, 1946.
The bikini is perhaps the most popular female beachwear around the globe, according to French fashion historian Olivier Saillard due to "the power of women, and not the power of fashion". As he explains, "The emancipation of swimwear has always been linked to the emancipation of women."