Conductors, Insulators and Semi-Conductors: Diode
When N and P-type semiconductor materials are joined together to form a single crystal a Diode is created. The diode allows electron flow in one direction only.
A diode has a forward bias when the Anode (P-material) is connected to B+ and the Cathode (N-material) is connected to B-.
Reversing the source voltage on the diode will result in current flow stoppage. This is called reverse bias.
Diodes are rated for specific voltage and current flow. The diode can not withstand unlimited forward bias and current flow.