There are two types
Interest Only is as the name implies, you only pay the interest on the amount you have borrowed. At some stage in the mortgage you would have to make some over-payment, lump sum payment or make other investments to ensure you can pay the amount you borrowed back at the end of the mortgage term. The other alternative is to sell the house.
Capital and Interest Repayment this type of mortgage will ensure that you repay the amount you borrowed as you go along. At the end of the mortgage term your home will belong to you.
Term of Mortgage
Mortgage terms range from 5 years to 45 years the choice is yours generally though monthly costs tend to dictate the length of time you choose.