(Noun) The purchaser of a commodity or service.
Original Source: Derived from Merriam-Webster.com: Customer
(Noun) A source of revenue for the service.
Description: If the service is part of a profit center, the customer is the person actually purchasing the product (e.g., demand deposit banking). If the service is part of a cost center (e.g., a human resources system), the customer is best seen as an internal executive, as the actual revenue-producing customers are too far removed.
Original Source: Derived from the Digital Practitioner Body of Knowledge™ Standard | Doc. No. C196