The worker forwards (interest free) typically 1-2 weeks work. The owner forwards (interest free) the workers pay untill all the product is sold. If the risk were a bad one, and the sale is at a loss, the worker is still paid, out the the owners additional saved money. The worker is guarenteed his wage, the owner is not.
The worker is welcome to. He's working, he can save some money instead of spending it all. That saved money is called "Capital".