What term describes the cost of borrowing money expressed as a percentage per year?

The term that describes the cost of borrowing money expressed as a percentage per year is the interest rate. This is a crucial concept in finance and economics as it quantifies the expense incurred by a borrower for using someone else's money. The interest rate is typically expressed as a percentage and can vary based on several factors including the timeframe, the credit risk associated with the borrower, and market conditions.

Understanding interest rates is vital for both individuals making borrowing decisions and businesses managing their financing strategies. When taking out loans, borrowers must consider the interest rate to understand the total cost of borrowing over time, as higher rates can significantly increase the amount that needs to be repaid.

The other options, while related in the realm of finance, do not correctly define the stated concept. Interest generally refers to the actual cost of borrowing money, but without the percentage per year aspect. Advertising and target marketing pertain to promotional tactics rather than financial costs.