ESC differences

Hi

I have this 2 kind of ESC, and I really dont know the difference, beside the size and the weight, wich one is better? Why the big one has capacitaros?

Here are the links of each one

https://www.rc-wing.com/arris-30a-opto-esc.html
https://www.rc-wing.com/flycolor-x-cross-bl-32-35a-2-6s-dshot-brushless-esc.html

Thanks!