Fixed-rate mortgages are the most common mortgage for many homebuyers because the monthly payments are stable. The interest rate you lock-in will be the same interest rate you pay for the life of the loan - whether it's a 15-year or 30-year mortgage.

Adjustable-rate mortgages (ARMs) are popular because they usually start with a lower interest rate and a lower monthly payment. The lower rate (and lower monthly payments) may also allow a higher loan amount. However, the interest rate can change during the life of the loan, which would mean that your monthly payment would increase (or decrease).

Balloon/reset mortgages have monthly mortgage payments based on a 30-year amortization schedule, and you have a choice at the end of the 5- or 7-year term to either pay off the remaining balance or reset the mortgage. So you have the advantage of a low monthly payment, like someone with a 30-year loan, but you must pay off the loan at the end of the specified term.