when establishing a corporation owners may choose to issue stock to raise capital companies then divide their stock into shares which are sold to investors these investors are generally investment banks or brokers that in turn sell the shares to other investors individually or through instruments like a mutual fund or exchange traded fund 
shares are the equivalent of ownership in a corporation because they represent ownership not debt there is no legal obligation for the company to reimburse the shareholders if something happens to the business however some companies may distribute payments to shareholders through dividends others may elect not to do so preferring to put all revenues towards operation growth and securing the company s future 