Fee Estimation – How do I understand Bitcoin transfer fees?

Currently https://bitcoinfees.net displays the following chart:

Therefore, 55 – 57 sat/vB is required for a transfer to occur in approximately 1 hour.

How do I interpret this chart? For example, what is the fee for a 1-to-1 transfer?

Or, if I am transferring from 2 wallets to 400 wallets, what is the fee per wallet (assuming that for 400 wallets the fee is split equally per wallet). So one wallet can receive $10 USD worth of BTC and the other wallet can receive BTC. One person can receive US$400). (This is a scenario for how mining pools pay miners.)