Hijab in Arabic means "barrier". While in Islamic scholarship, hijab itself more refers to the appropriate dress code and close aurat according to the religious shari'a.
Some people think that every hijab is a Hijaab. But not all Hijab is Hijab. As explained above, Hijab is derived from the word hajaban which generally means covering something. Can be a border curtain, mosquito net, divider board, or other aling-aling.