Pyjamas are generally two-piece garments but can be in a single-piece too.
A nightgown is a loosely hanging nightwear for women, though men may prefer it too. It may vary from being hip-length (baby doll) to ankle-length (peignoir).
Women's nightwear has been heavily inspired by the trends portrayed in Sex and the City, the TV show about four fashionable women living life by their rules in Manhattan.
Trends in women's pyjamas incline towards loungewear items like strappy vest-like tops and tees.