Is this a "side job" or a "business"? Which to choose?

I have a vendors license and I might sell a few pieces of artwork a year. So yes it is a business and I file a Schedule C every year even though I sell very little. Should I choose that this is a "side job", or this is a business? Because I don't do much with it. First time filing my own taxes. Just didn't know which to choose or why?