What is a debit dishonour fee?

Excuse me, could you please explain what a debit dishonour fee is? I've heard it mentioned in relation to bank accounts and transactions, but I'm not entirely sure what it entails. Is it a penalty that's charged when a payment is not processed successfully? And if so, under what circumstances would such a fee be applied? Additionally, how much does it typically cost, and is there any way to avoid incurring it? Your insight would be greatly appreciated.