Florida mortgages are loan arrangements; they're loan arrangements that require the borrower to put up interests in real estate that they own or will own, in order to secure the loan. What this does is place certain restrictions on what both the lender and the borrower can do about the property (as opposed to what the outright lone owner would be able to do with the property, had that owner paid for the real estate in full, in liquid funds). In the United States, these mortgages and the general area of finance that these loan arrangements exist in, is heavily regulated.
First, the interest rates offered to borrowers are directly affected by the interest rates set by the Federal Reserve Bank (which sets the interest rates at which they'll issue cash capital, to participating member banking institutions), though there isn't a concrete cause and effect dynamic in place here; for example, "the Fed" could lower interest rates, and lending institutions that offer Florida mortgages could simply decide to keep lending at their higher interests. What happens, usually, however, is that one bank ends up lowering interest rates, in order to do more business than the next bank, and a sort of pricing war ensues. This usually happens when a lower interest rate comes about as a sort of surprise to member banks. There are those in the media that are somewhat suspicious of the Fed and the banks, and the general dynamic between the two.