Mortgage - The security created on the property by the lender, which will usually include certain restrictions on the use or disposal of the property (such as paying any outstanding debt before selling the property).  In other words this is the amount that you are going to have to pay to own the house. 

Amortization - Amortization is the distribution of a single lump-sum cash flow into many smaller cash flow installments, as determined by an amortization schedule. Unlike other repayment models, each repayment installment consists of both principal and interest.

Payments are divided into equal amounts for the duration of the loan, making it the simplest repayment model. A greater amount of the payment is applied to interest at the beginning of the amortization schedule, while more money is applied to principal at the end.

Principal - The money originally invested or loaned, on which basis interest and returns are calculated. In other words, the original amount lent.

Interest - A fee paid on borrowed money. The fee is a compensation to the lender for foregoing other useful investments that could have been made with the loaned money. The amount lent is called the principal. The percentage of the principal which is paid as fee (the interest), over a certain period of time, is called the interest rate.

Term - The agreed upon years to repay the loan (mortgage).

Down Payment - The percentage of the loan that you must pay upfront.