They send a representative, probably someone from their legal department if they have one. The important thing is that both you and the company are arguing on much more level footing. You don't need to be thoroughly versed in court procedure, and the whole process is generally a little more lax than in superior court.

With that said, the company can still pump tons of money into things behind the scenes, but because the stakes are so low, and not necessarily precedent-forming, they're not likely to actually invest that much money into fighting you. And even if they do and you lose, since you brought the lawsuit and there are no attorney fees, the most you'd end up spending is the court fees (potentially the company's court fees, but those are minimal too.)