What's the difference between a symmetric and asymmetric park ski?

Symmetric park skis have identical tip and tail dimensions and sidecut, so the ski performs exactly the same riding forward or switch. This is ideal for pure park riding where switch performance is paramount. Asymmetric park skis have slightly different tip and tail shapes—often a slightly longer tip with more rise and a shorter, lower tail. This provides better forward performance and flotation while still allowing switch riding, making them more versatile for skiers who ride the whole mountain.