mosfet - Why does this Bridge Rectifier claim to have no [Diode] Forward Voltage drop

I was, "OK, this is feasible"... But then I traced how it worked and it simply blocked current through Drain and Source when a P and N pair are reverse biased; then when the other P and N pair are forward biased current flows through Forward Diodes; then alternatingly... Then it's the same, one is just using diodes to Bridge Rectify. Worse still, MOSFETs generally don't have a low diode voltage drop... Or maybe I'm missing something here....

Answer

Just look at how the biasing works: -

With positive on the top input rail the lower left N channel FET is switched on and, with negative on the bottom input rail the top right P channel FET is switched on.