The sole proprietorship
It is a business owned by one person (sole proprietor) and not incorporated.
A partnership is an association between two or more individuals, corporations, trusts or partnerships that come together for the purpose of carrying on a business.
A joint-stock company
The joint-stock company is a separate legal entity with share capital. We then distinguish each owner of the company by the term shareholder. When the company is formed, the owners transfer money, goods or services to the company in return for shares.
The corporation must file a separate tax return for each shareholder.