A mortgage is a loan taken out to buy a house. Your mortgage will be secured against the value of the home you plan to buy. You pay the mortgage back in monthly installments with added interest until the full amount is paid off. The typical repayment period is 25 years, although you can get shorter or longer terms.
Most people will need a mortgage to buy a house as it is a significantly large amount of money to borrow. There are many different types of mortgage that come with varying interest rates, too.