A tanga is a type of panty.
It has a narrower back than a traditional panty, but is not as narrow as a thong. It has thin straps across the hips and sits low on the hip, exposing the gluteal fold and some of the buttocks. Sometines a bikini bottom is cut as a tanga.
Originally, a tanga was a loincloth worn by indigenous peoples in tropical America; the current meaning dates from the 1970s.