Can 1 smart contract perform multiple functions or is new contract needed for multiple tasks? For instance, let's say I built en eCommerce store that sold pre-made Wordpress Themes, a digital product. Can I setup just one smart contract that dispenses different themes at different prices or do I need a new contract for every different item, or at the very least, every different priced item? Can the contracts be set to be recurring or do they auto void after one use? I'm kind of researching a lot of this as I go so I may be ignorant in my understanding in how it all works at all and my questions may not even make sense.