A hijab, is a veil that covers the head and chest, which is sometimes worn by some Muslim women beyond the age of puberty in the presence of adult males outside of their immediate family as a form of modest attire. According to some interpretations, it may also be worn in the presence of adult non-Muslim females outside of their immediate family. The hijab can further denote any head, face or body covering worn by Muslim women that similarly conforms to a certain standard of modesty. It can also be used to refer to the seclusion of women from men in the public sphere, or it may embody a metaphysical dimension – Al-hijab refers to "the veil which separates man or the world from God". In fact the word "veil" derives from a Latin word which means much the same as hijab.
Most often, the hijab is worn by Muslim women as a symbol of modesty and privacy. Here's a video tutorial on how to wear the hijab with style: