What is the nature of (a) a credit memo issued by the seller of merchandise, (b) a debit memo issued by the buyer of merchandise? Name three accounts that would normally appear in the chart of...

What is the nature of (a) a credit memo issued by the seller of merchandise, (b) a debit memo issued by the buyer of merchandise?

Name three accounts that would normally appear in the chart of accounts of a merchandising business but would not appear in the chart of accounts of a service business.