It's a continuum. Employment is for smaller time increments, and the enforcement is handled by a third party. That said, you might want to reconsider things in

It's a continuum. Employment is for smaller time increments, and the enforcement is handled by a third party. That said, you might want to reconsider things in both directions. If someone has a very short time horizon, but is capable of doing useful labor, a slave owner will probably treat them better than they'd treat themselves. This is a very reactionary view, which happens to be exemplified by the progressive political movement -- conservatives are okay with letting somebody, e.g., survive on payday loans and live in a flophouse; liberals would rather own more of their economic output and constrain their freedom for their own good.