It is worn by Muslim women as a symbol of modesty,

Privacy and morality. According to the Encyclopedia of Islam and Muslim World, modesty in the Qur'an concerns both men's and women's "gaze, gait, garments, and genitalia." The Quran admonishes Muslim women to dress modestly and cover their breasts and genitals,but does not specify that women cover their heads, faces or bodies. Most Islamic legal systems define this type of modest dressing as covering everything except the face and hands in public.These guidelines (for covering of the entire body except for the hands, the feet and the face), are found in texts of fiqh and hadith developed after the revelation of the Qur'an.