The main reason that people invest in stocks and shares is that if they're successful, you can potentially make more money by doing this than simply leaving money in a bank or building society account. The interest rates in banks and building societies are set and don't move much, whereas a successful investment can get a much better return on your money. Also, investing in a company sometimes entitles you to certain privileges or perks, which will be made available when you become a shareholder.
