What is the difference between private sector organization and public sector organization?

What is the difference between private sector organization and public sector organization?
Understand that your Q can also be taken to mean the differences in organization between "public" and "private" companies, but v entities, there are lots of differences, chiefly stemming from their difference in focus; one is organized for profit or other gain, and the other for service. In the first case, it's basically the difference between the ultimate power resting with a king, or a board of directors.