Whats the difference between each mascara brush?

whats the difference between each mascara brush. some are straight while others are curved. why is that and what does each mascara brush do?Whats the difference between each mascara brush?
different shapes r for different eye shapes and thickness of ure lashes.


ex. if u dont have alot of lashes u wana pick up those lil lashes on the edge sides of ure eyes (the thin ones) so by brushing those with mascara will give u more lashes to show and u can pick those easier with the curved mascara the straight ones, but for people who have too much lashes they just want a tint of length and not that much thickness so they use the straight ones


if that makes any sence.Whats the difference between each mascara brush?
its to fit the cheekbones on ur face since ever1 has a different face