With a fixed rate loan your payment generally stays the same through the life of the loan.
You can get a lower interest rate for shorter term loans, for example if you chose a 15 yr.
vs. a 30 yr. You'll get a lower payment with a longer term however you'll pay a lot more interest,
and therefore more on the total loan throughout the loan life.
Payments on adjustable rate mortgages (ARMs) change through the life of the loan. Adjustments are made
to the interest rate of the loan based upon the defined index the loan uses, such as a Treasury Bill
(T-Bill) or Cost of Savings Index (COSI) or many more. Arm Indexes Explained
If you really want some heavy reading on ARM loans, check out the Federal Reserve Board's
Consumer Handbook on Adjustable Rate Loans
Fixed or Adjustable? See which loan is right for you
Glossary of adjustable rate mortgage terms: Federal Reserve ARM Glossary