The Finance modules handles transactions between your Organisation and its Customers:

• Invoices: Which are used to charge a Customer for a single Job, multiple Jobs, or standalone Labour, Parts, Fees, and Expenses.
• Credit Notes: Are negative Invoices, used to refund a Customer and pay a later Invoice.
• Cash Receipts: Money received from a Customer against one or more Invoices.
• Credits: Payments made in advance that are not yet applied to a specific Invoice.