Most people will need a mortgage to finance the purchase of a home. A mortgage works much like any other loan: You borrow money from a bank, credit union or other lender and then pay it back over time. The main difference? A mortgage is the largest loan that most consumers will take on during their lifetimes. Because of this, it is important for home buyers to understand exactly what goes into a mortgage and what will be required from the prospective home buyer to obtain one.