It is a way to buy and sell the shares in publicly listed companies. They are lot of ways to start investing in shares. They are broker's that deals with this type of investment business. You have to make sure you find the good ones. Some of them they are charging a lot of money to invest with them. Some of companies you can invest without broker. You have to do research so that you can found a best share dealing. Lot of people they just jump to start working with a company without doing research that why they end up in scams. You must buy in a low price and sell it with a high price. In that way you can make a lot of profit. If you can't make profit, you must change your investment portfolio. The reason for doing this is to build your investment portfolio. If you have smart phone or laptop you can start earning money online. It is easy to do it because there is a lot of information in the Internet. Everyone can do it.