Final answer:
Compound interest differs from simple interest in that it includes interest on the previously earned interest, leading to a growing amount over time. Therefore, the correct option is B.
Step-by-step explanation:
One key difference between simple interest and compound interest is that compound interest involves interest on interest. While simple interest is calculated only on the principal amount of a loan or investment, compound interest is calculated on both the principal amount and the accumulated interest over time. This means that in compound interest scenarios, the amount of interest earned grows because each period's interest calculation is based on the increasing amount of the principal plus the interest that has been added in previous periods.