When the word "while" is used here in this instance;
Did you know that crocodiles tend to have longer, pointed, V-shaped snouts <u><em>while </em></u> alligators generally have wider, rounder, U-shaped snouts?
The "while" is comparing the snouts of crocodiles and alligators, saying crocodiles have V-shaped [pointy] snouts and alligators have U-shaped [round] snouts.
