a. Principle - is the amount of money you borrowed
b. Interest - is the fee the bank/lender charges for the use of their money/loan
c. Taxes - apply to the property itself and are based on the rates the city/county in which the property is in has determined. Taxes are a big part of owning a property, as they can cost the homeowner thousands of dollars per year. Taxes can be built into the mortgage via an escrow account however if not included in escrow you are responsible for timely payment on your own.
d. Insurance - lenders require that the property from which you are seeking a mortgage
are covered by homeowners insurance. In almost all cases, the price of this insurance is included into the monthly mortgage payments.