Why is a giant panda different to a normal panda?

There is no difference between bears and pandas, since pandas are bears. But their are differences between the different types of bears. (Sun bear, Asian black bear, black bear, brown bear, polar bear.) It just depends on the area you are in (different climates, geography, food/hunting, etc.) that you find the different types of bears.

Panda bears in specific are native to China. They belong to the order Carnivora, but 99% of their diet consists of bamboo.