A puffin crossing (pedestrian user-friendly interface) is a type of pedestrian crossing in use in the United Kingdom.
It differs from a pelican crossing in that the lights controlling the pedestrians are on the near side of the road, rather than on the opposite side, and the existence of an extra detector for pedestrians, either on-crossing or kerb-side.
An on-crossing detector will ensure that the signal for vehicles remains red until the pedestrians have finished crossing (within practical limits). A kerb-side detector will cancel the pedestrian demand should the pedestrian move away from the kerb side, when the pedestrian is crossing in a gap or does not use the crossing.
See pelican crossing for basic information.