The interest rate doesn't change throughout the life of the loan. It doesn't matter how market interest rates rise or fall. Advantage: Monthly mortgage payments will always remain constant, making monthly cash flow more predictable. Disadvantage: They carry a higher interest rate because if interest rates rise, banks lose the opportunity to make more money on the funds they're lending to you. 

In an ARM (Adjustable Rate Mortgage), the interest rate adjusts over the life of the loan according to a pre-established formula, which is related to the fluctuation of interest rates in the financial market.

• Advantages: They initially have a lower interest rate because the risk of a possible interest rate hike is shared with the bank. Ideal if interest rates are on the decline.
• Desventajas: Pueden resultar más costosas que un préstamo de tasa fija si en el largo plazo sube la tasa de interés.  

The Federal Housing Administration (FHA) is a federal agency whose primary objective is to provide housing opportunities for families with proven income but poor credit or limited down payment options. The agency does not provide mortgage funds, but rather insures loans made by banks.

FHA loans apply to single- or multi-family homes. The advantage for many buyers is that FHA loans require a low down payment of only 3.5% and also offer a competitive interest rate. However, these loans require private mortgage insurance, or "PMI," as it is known under these loans, which is included in the monthly payment.

These are loans for people with credit problems who are willing to put down a 35% or more down payment or who want to refinance and owe 65% or less of the home's value. They have less stringent qualification criteria than regular loans, but charge much higher interest rates.

These are temporary loans, generally less than three years, designed to help people with credit problems develop a financing plan so that as soon as their credit and financial circumstances improve, they can refinance at a lower interest rate.