The term raptor is given to any bird that kills prey with its feet (talons). These incude Eagles , Falcons , Hawks , CaraCaras , Secratery birds , some Vultures and Ospreys. Owls are not raptors , but they are still birds of prey. A Heron , Kingfisher or Crows is not a raptor because they kill and hunt with their beak , and they do not posses the raptor characteristics.
In other terms , raptor can also be used for a carnivourus dromaesaurid bipedal dinosaur such as velociraptor or Utahraptor.