The marketing mix is a business tool used in marketing and by marketers. (Wikipedia)
A planned mix of the controllable elements of a product's marketing plan commonly termed as 4Ps: product, price, place, and promotion. (Business Dictionary)
Product = A product is seen as an item that satisfies what a consumer demands. It is a tangible good or an intangible service. Tangible products are those that have an independent physical existence.
Price = The amount a customer pays for the product.
Promotion = All of the methods of communication that a marketer may use to provide information to different parties about the product.
Place = Refers to providing the product at a place which is convenient for consumers to access.
Physical Evidence = The environment / evidence which shows that a service was performed, such as the delivery packaging for the item delivered by a delivery service, or a scar left by a surgeon.
People = The employees that execute the service, chiefly concerning the manner and skill in which they do so.
Process = The processes and systems within the organization that affect the execution of its service, such as job queuing or query handling.