It depends on what type of mortgage you obtained. In the case of an interest-only mortgage, as the name says, you will be making payments that include the full interest of the loan. But your lender might require that he pays taxes and insurance on your behalf and would want you to pay 1/12 of the yearly amount on a monthly basis into an escrow account.
That way the lender can insure that taxes and insurance are paid on time and his collateral is not endangered buy negligence to pay one’s bills. Keep in mind that the loan amount on an interest only mortgage will always stay the same. No matter how long you pay you will still owe the original loan amount to your lender at the end of the term.

If you signed up for a more traditional full amortization mortgage you monthly payment will include the full interest on the loan plus an amount that will insure that the loan will be repaid over an greed period of time (for example 30 years).
Think of the amortization amount as putting money in a savings account. only the interest you earn on the savings is equal to the percentage rate of your mortgage. As lenders try to earn more interest on the loans they grant than banks offer for deposits you are actually receiving a much higher interest rate on these quasi savings that if you saved into a money market account. Again you payment could also include taxes and insurance that the lender will pay on your behalf.