If you keep this regularly, this can be a record that shows a part of family history. But most people find it's not easy to do so. Basically, this allows you to store and display your daily, weekly, or monthly spending and income, and helps you see how much is left over for other things. So this can be used as a guide in planning future spending. This will help you to think over your spending habits. Nowadays more and more people keep this using computers.