Just a clarification of Webster's entry here.
  • The British hawk (Latin name accipiter) is very falcon-like in appearance and behaviour; with pointy wings and a long, narrow tail, it catches its prey in flight, using its speed.
  • The British buzzard (Latin name buteo) is a small eagle in appearance and behaviour; with large, broad wings and a short, wide, rounded tail, it slowly flaps or hovers, and circles at great height in search for small animals on the ground.

In America, on the other hand, "hawk" is a general word for a bird of prey, but usually refers to buteo birds, of which there are many species there.