Shares are issued by companies and provide you with a level of ownership based on how much money you invest.
Shares of public companies can be readily bought or sold on stock exchanges through a stockbroker.
When you buy a company's shares directly, you're buying a financial interest in its potential growth.
The value of your investment is determined by the company's share price, which generally will move up and down on a daily basis depending on a range of factors.
You may also receive ongoing income payments if the company chooses to pay dividends.
There are more than 2,000 companies listed on the Australian Securities Exchange (ASX) alone, with the top 300 listed companies making up most of the market's total value.