Nature: A share is a part of the capital of the company and a debenture is a part of loan of the company.
Dividend or Interest :Dividend on shares is paid only when there are profits in the company on the other hand debenture interest has to be paid, it the company does not have profit or even suffer a loss.
Ownership Equity share holders are the owners of the company on the other hand debenture holders are the creditors of the company.