A mortgage is a type of loan specifically used to purchase real estate, typically a home or a piece of property. It involves borrowing money from a lender, such as a bank or a mortgage company, with the understanding that the borrowed amount will be repaid over a set period of time, usually ranging from 15 to 30 years.

The key components of a mortgage include:

1. Principal: This refers to the initial amount of money borrowed to purchase the property.

2. Interest: Lenders charge interest on the loan, which is the cost of borrowing the money. Interest rates can be fixed (stay the same throughout the loan term) or adjustable (fluctuate according to market conditions).

3. Term: The term of the mortgage is the length of time over which the loan must be repaid. Common mortgage terms include 15, 20, or 30 years.

4. Monthly Payments: Borrowers are typically required to make monthly payments to repay the loan. These payments usually consist of both principal and interest, with additional amounts sometimes included for property taxes and homeowners insurance. This combined payment is often referred to as the PITI (Principal, Interest, Taxes, and Insurance).

5. Collateral: The property being purchased serves as collateral for the loan. This means that if the borrower fails to repay the loan as agreed, the lender has the right to seize the property through a process called foreclosure.

Mortgages are a common way for individuals to affordably purchase homes without having to pay the full purchase price upfront. However, it's important for borrowers to carefully consider the terms of the mortgage and ensure they can afford the monthly payments, as failure to repay the loan can result in the loss of the property through foreclosure.