STPM33 reference circuit. I did not understand.

I am trying to use STPM33.

I am designing a circuit with reference to the reference circuit.

The circuit I'm looking at is the 'EVALSTPM33' circuit from the STPM33 kit.

I have two questions.

1. Many circuits are falling to ground. What is the difference between ground and F in the reference circuit?

The N part is not best understood.

2. What is the circle marked 1500ohm? 'EVALSTPM33' does not have a 1500ohm resistor.

I'm not good at English so I used Google Translator.

Attached photo

Thank you for reading my question.