Sole Proprietorship: If you are disabled, the business will falter unless family, friends, or employees are willing and able to substitute for you. Death of a sole praetor means the end of the business, but heirs can inherit the assists of the business. Your heirs can start a new business using the same address and location, providing your creditors are paid.
Partnership: If one partner is disabled, the other may be able to fill I until the disable partner recovers. One partner cannot sell his/her share in a partnership without getting the consent of the other partner(s). Death dissolves a partnership automatically. Heirs for a partner inherit his/her share of the partnership assets. Without a partnership agreement the heirs often have to sue to enforce their legal rights.
Corporation: A corporation is a separate legal entity. Its existence is not affected by death or disability of shareholders. Share of stock can be sold of one owner wants to leave the business. On the death of a shareholder, the stock goes to the shareholder's heir.