Yes these are unisexual flowers, in this case, male. The form is unusual to most people, but common for many types of trees. The definition of catkin that PlantLadyLynn cites is correct, but your example is not a catkin, as you can see it is neither scaly or spike-like. Without getting overly technical, call them pendulous male flowers. Close inspection of the tree would also reveal the female flowers that again would seem quite unusual, and also very unlike the male flowers on the same tree.
It's too early in the season to correctly identify the tree, but a good guess would be something in the maple family (Aceraceae).