As you probably know, cheetahs and leopards look very similar and many people mistake cheetahs for leopards or the opposite. Look at two images of a leopard and a cheetah, then you'll see that they're very different from each other.
1. Cheetahs are much more lanky, having a thin stomach for easier running. But leopards have more muscles, though I may not know much about leopards, but I'm guessing it's for hunting purposes.
2. Cheetahs have a larger chest because they have extra large lungs and heart so they can withstand their large bursts of energy.