Part 2: Bias
When a positive
voltage is applied to the anode the diode is said to have forward
bias. When it is forward biased (and the voltage exceeds the barrier
voltage) it will conduct.
When the voltage
is reversed, the diode is said to have reverse bias. When it is
reversed biased, it will not conduct unless the voltage is so high
that it exceeds the breakdown voltage of the diode.
come in a range of sizes: the cathode is usually identified by a
stripe at one end of the package.