A loose term describing the general percentage rate of profitable return, or interest rate payable on a loan or capital investment. Related to time, quoted as a percentage it's the rate of upside from an investment.
How much did I make ? a) $100 invested, $110 back in 2 years = 10% total return b) $100 invested, $110 back in 12 months = 10% annual rate of return. Spot the difference? They are both 'Rates Of Return' but slightly different measures.