Turbans are not required of all Muslim men, but those who wear them do so for a variety of reasons. Perhaps the most important reason is in emulation of the Prophet Muhammad, who is believed to have worn either a white or a black turban. Emulation of the Prophet is generally encouraged among Muslims even in seemingly superficial matters such as clothing.
Other reasons to wear a turban include affiliation with a specific school of Islam, regional custom and personal preference. Muslim scholars and theologians often wear white turbans as a badge of office, though Shiite clerics often wear black. Turbans are also useful for identifying individuals of a high station. A black turban wrapped around a white cap is popular among Shiite men who claim descent from the Prophet, while others often choose green as an homage to the traditional color of Paradise.
Some Muslim men wear turbans for reasons that are not necessarily religious. Among the largely Muslim populations of the Sahara desert, for example, turbans can be pulled over the face to shield the wearer from windblown sand. Muslim women generally do not wear turbans, though wearing turbans is not explicitly forbidden for women in most Muslim traditions.