I honestly have no clue how to do any of these questions. Describe how a PN junction works. How are diodes used in circuits.

I honestly have no clue how to do any of these questions.

1. Describe how a PN junction works.

2. How are diodes used in circuits. Please don't provide an answer to the question "how does a diode work". If you write a few sentences based on "a diode only allows current to flow in one direction", you will get no credit for your answer.

3. Given the answer to question one, describe how an N channel MOSFET works.