Laws concerning corporations fill volumes, especially since they vary from state to state. While the sole proprietorship or the partnership is a legal entity in which you are the whole, or part of the whole, a corporation is an entity unto itself. You, and any others, are just stockholders in the corporation. If you would die, the corporation could still remain in existence.
One of the main reasons for incorporating is the limited liability of the corporation's stockholders. Instead of a sole proprietor or a partner being held accountable for a business debt, the corporation bears the accountability. A corporation may have one stockholder, the business owner. Sometimes this may protect the business owner's personal assets from a corporation debt.