A company is a type of organization or a business in which there is more than one owner.  This company can have different levels of protection for the owners of the company and may be traded on the public trading block, although private trading is also possible.  These different levels of protection and involvement by the owners or shareholders have different names and can be identified by such.

A company limited by shares indicates that the only loss that the investors can be responsible is the amount that was invested into the company.  For example, if an investor were to invest $200 into a company that ended up defaulting on hundreds of dollars of loans, the investor would be out the $200 and not responsible for the loans by the company.  This type of ownership does limit the involvement of the investor to those investors who have the highest quantities of stock with the primary voter being the one with the most stock.  An owner of the company would be one who owns more stock than the rest combines, usually 51% of the stock.  This is the most common form of a company.

In the investing world, there are private and public companies.  The private companies are not traded in the public market and often have rules restricting the sale of the stocks.  This keeps the ownership of the company within the company or a family while maintaining the company standards.  The publicly traded stock is more common and is often regulated by the stock exchange.  This form of stock typically carries no restrictions and offers everyday consumers a chance to buy into a specific company. This ownership is at the heart of the stock market and stock market trading.