A more thorough explanation:

An invoice book is a type of journal used to record invoices. It is a book with pre-printed invoice forms that are filled out by hand or printed out using a computer. The purpose of an invoice book is to keep track of sales and payments made by customers.

• When a customer purchases a product or service, the seller will fill out an invoice form in the invoice book. The form will include details such as the date of the sale, the name and address of the customer, the items purchased, and the total amount due.
• At the end of the day, the seller will add up the total amount of sales recorded in the invoice book and compare it to the amount of cash or checks received from customers. This helps to ensure that all sales have been properly recorded and accounted for.

Overall, an invoice book is an important tool for businesses to keep track of their sales and payments. It helps to ensure that all transactions are properly recorded and can be used as a reference in case of any disputes or discrepancies.