I think that looks more like fixture to me cause its hanging from the ceiling. And its also close on all ends there isn't at least one side open for air.
:happyfish The reflector is the metal thing that wraps around lights to reflect the light. The reflector is attached to the canopy. I think the guy before me is right about it being a fixture because it is hanging.
Canopy or Hood or Fixture
Whatever word you use is personal preference and still describes the same basic object. Kind of like the "Pop vs. Soda vs. Coke" debate on how to refer to carbonated beverages!
By the way, it's called pop.