Stocks (also called stock or share) are part of the capital stock of a company. It represents the original equity that was paid into the company. The capital stock is divided into shares that could be traded at stock markets like the New York Stock Exchange (NYSE) or NASDAQ. Every stock or share represents a partition ownership to the company. A stock owner has the ability to receive dividends as well as to participate on the business opportunities and risks.
There are two main stock types available: common stock and preferred stock. A common stock gives the shareowner the ability to vote at the annual general meeting and to receive dividends. A preferred stock has no voting right but for compensation, a higher claim for earnings and assets.
What are Stocks? Here is a video from Investopedia about stock: