The only difference is that you take a new loan for more than what is owed on the current loan and you pocket the difference.
Even with a low credit score, you can refinance your mortgage to lock in low flow.

A home loan refinance interest holder in relation to a mortgage purchase rate.

The federal truth in Lending Act makes it mandatory for companies to disclose the APR refinancing in all loan agreements.

This offer variable interest that are always that credit cards because your loan is secured.

However, before you go to an ARM, simply answer a very important question: Can you afford to continue to pay the loan if interest rates rise? If the answer is yes, then by all means, go ahead.