Network as a service (NaaS) describes services for network transport connectivity.

NaaS involves the optimization of resource allocations by considering network and computing resources as a unified whole.

Accounts receivable is a legally enforceable claim for payment held by a business for goods supplied and/or services rendered that customers/clients have ordered but not paid for.

These are generally in the form of invoices raised by a business and delivered to the customer for payment within an agreed time frame.

Accounts receivable is shown in a balance sheet as an asset.

It is one of a series of accounting transactions dealing with the billing of a customer for goods and services that the customer has ordered.

These may be distinguished from notes receivable, which are debts created through formal legal instruments called promissory notes.

Accounts payable is money owed by a business to its suppliers shown as a liability on a company's balance sheet.

It is distinct from notes payable liabilities, which are debts created by formal legal instrument documents.

Business-to-business (B2B) refers to a situation where one business makes a commercial transaction with another.

This typically occurs when:

Electronic invoicing (also called e-invoicing) is a form of electronic billing.

E-invoicing methods are used by trading partners, such as customers and their suppliers, to present and monitor transactional documents between one another and ensure the terms of their trading agreements are being met.

These documents include invoices, purchase orders, debit notes, credit notes, payment terms and instructions, and remittance slips.