Fixed rate mortgages are mortgage loans that offer the same interest rate throughout the life of the loan. They account for the majority of loans availed by borrowers. The most common loan terms are 10 years, 15 years, and 30 years.
Mortgage rates that change interest rate after a fixed period are called adjustable rate mortgages. They are way riskier since the rates may bounce to unpredictable extremes. However the interest rates offered are lower compared to fixed-rate mortgages to compensate for this risk.