## Interest basics

### Interest is a fixed charge for borrowing money, typically represented as a percentage of the total amount of money borrowed.

Compound interest means that interest is earned not only on the principal (the sum originally borrowed), but also on all interest previously earned at specified compounding periods. The interest portion of a specific payment on a bond, mortgage or other loan can also be computed given a loan amount, interest rate, number of compounding periods and specified period number. Plots are automatically generated to show useful context for each type of interest computation, including amortization tables and charts visualizing relative amounts of principal and interest paid on a given loan.