In accounting there are two common uses of the term stock. One meaning of stock refers to the goods on hand which is to be sold to customers. In that situation, stock means inventory.
The term stock is also used to mean the ownership shares of a corporation. For example, an owner of a corporation will have a stock certificate which provides evidence of his or her ownership of a corporation's common stock or preferred stock. The owner of the corporation's common or preferred stock is known as a stockholder.