Standard variable rate
Morgages on Standard Variable Rate (SVR) is a type of interest rate that moves with the movements in the international money market. This means that if the general interest payable in the money market is low, then the SVR will decrease accordingly.
Likewise, if the general money market interest rises, so will the SVR.
Morgages on Standard Variable Rate are more freely managed than morgages on fixed rate, since they can be repayd earlier and refinanced without a penalty.
Reference: The Penguin Dictionary of Economics, 3rd edt.