Box 1, The Annual Percentage Rate or APR is what you are charged each year to finance the purchase.
Box 2, Finance Charge uses the APR to calculate the dollar amount to finance your purchase over the life of the contract. Learn more about finance charges here.
Box 3, Amount Financed, comes directly from the last line of the itemization section, shown below. This figure is the price of the vehicle, plus taxes, fees, and optional add-ons like an extended service plan, minus any down payment (cash, trade, and rebate).
Take your time reviewing the itemization table and if unsure of any amount, ask the dealer for clarification.