Essentially without science we can define women and men by saying women make babies and feed infants and men do not make babies or feed infants freeing them up to do other things with their time.
Women are unique because they are the natural carers of children and in most cases the most efficient carers. Women are unique because they can get pregnant and nurse babies. Women were designed through evolution to stay very close to their children. Being close to your kids does not mean being the sole or even primary care giver though; it just means being close enough to them so that if they need you you will be present.
Read this to better understand your uniqueness: http://www.bobafamily.com/research/exterogestation-and-the-need-to-be-held/