What is the difference between void and refund when charging a card with preauth on flutterwave

I am trying to charge a card using the Flutterwave nodejs library. I want to use the preauth flow. What is the difference between void and refund in the preauth flow.

• in preauth, you put a hold on some money on the card

• in capture, you do a debit on some or all the money you preauth

• in refund, you return the money you captured

• in void, you remove the hold on the money you preauth

  so void is the reversal of preauth and refund is the reversal of capture