The term 'collar type' can refer to two different types of collars: the Eton collar and the Peter Pan collar. The Eton collar is a stiff, upright collar with a narrow opening at the front, typically worn with a bow tie. It is named after the Eton College in England, where it was first popularized. The Peter Pan collar is a flat, round collar with a scalloped edge, often seen on blouses and dresses. It is named after the character Peter Pan from the novel by J.M. Barrie.