It is part of the hijab family.
The niqab is similar in some respects but not identical to the burqa favored in Afghanistan or the chador favored in Iran. The three are often confused, although only pedants, nationalists and clerical sticklers are offended by the confusion.
Usually black, spartan and designed to efface personality and physical suggestions, the niqab is part of a full-body covering favored in Middle East countries east and south of the Levant, where the influence of fundamentalist Islam, or Salafism, is more pronounced. These nations include Saudi Arabia, Yemen, the nations of the Gulf Cooperation Council, and the tribal or rural areas of Pakistan. Since the 1970s, the niqab has made an appearance in Turkey, beginning in the east and migrating to the more urban west, as well as in parts of Europe where Muslim populations are significant, albeit in small numbers.
The niqab did not originate with Islam. The niqab, or face-coverings similar to it, were worn by Christian women in the Byzantine Empire and in pre-Islamic Persia. Islam adopted the practice, which was not, contrary to common perceptions, required by the Koran. Scholars, students and commonfolk in Islam are in the midst of a rich and varied debate over the importance, necessity or mere validity of the niqab and its sister-negators of the female body as required or even acceptable dress. The debate is nowhere near its conclusion.