How d c flow through diode?

In a diode, direct current (DC) flows in one direction, from the anode (positive side) to the cathode (negative side), when the diode is forward-biased. This occurs when the anode voltage is higher than the cathode voltage by at least the diode's forward voltage threshold (typically around 0.7V for silicon diodes). When reverse-biased, the diode blocks current flow, allowing minimal leakage, effectively preventing DC from flowing in the opposite direction. Thus, diodes act as one-way valves for electric current.