There are many definitions of marketing. The better definitions are focused upon customer orientation and satisfaction of customer needs. Just some few examples:

Marketing is the social process by which individuals and groups obtain what they need and want through creating and exchanging products and value with others. Kotler.

Marketing is the management process that identifies, anticipates and satisfies customer requirements profitably - The Chartered Institute of Marketing (CIM).

Marketing is abut the right product, in the right place, at the right time, at the right price - Adcock.

Marketing is essentially about marshalling the resources of an organization so that they meet the changing needs of the customer on whom the organization depends - Palmer.

Marketing is the process whereby society, to supply its consumption needs, evolves distributive systems composed of participants, who, interacting under constraints - technical (economic) and ethical (social) - create the transactions or flows which resolve market separations and result in exchange and consumption. - Bartles.

"Marketing is a four step process that begins with analyzing and defining a qualified universe of potential users or buyers. After this first phase in the marketing process, a true marketing effort succeeds in capturing the attention of the intended buyers within the targeted universe. Third, systematic effort must be put into getting the prospects to accept the concepts or propositions being offered via the marketing effort. Finally, with all three of the previous steps achieved, the marketer must convert the prospective buyer into an actual buyer by getting them to take the desired action (purchase, rent, call, download, subscribe, refer, sell, follow the law, become a member, etc.)." Norris

Marketing is the achievement of corporate goals through meeting and exceeding customer needs better than the competition.- Jobber.

The marketing concept is a philosophy. It makes the customer, and the satisfaction of his or her needs, the focal point of all business activities. It is driven by senior managers, passionate about delighting their customers.
Marketing is not only much broader than selling, it is not a specialized activity at all. It encompasses the entire business. It is the whole business seen from the point of view of the final result, that is, from the customer's point of view. Concern and responsibility for marketing must therefore permeate all areas of the enterprise. - Drucker.

This customer focused philosophy is known as the 'marketing concept'. The marketing concept is a philosophy, not a system of marketing or an organizational structure. It is founded on the belief that profitable sales and satisfactory returns on investment can only be achieved by identifying, anticipating and satisfying customer needs and desires. -Barwell.

Implementation of the marketing concept [in the 1990's] requires attention to three basic elements of the marketing concept. These are: Customer orientation; An organization to implement a customer orientation; Long-range customer and societal welfare. -Cohen.

The important elements of the definitions of marketing and the exposition of the concept and the philosophy of marketing are:
Marketing focuses on the satisfaction of customer needs, wants and requirements.
The philosophy of marketing needs to be owned by everyone from within the organization.

Future needs have to be identified and anticipated.
There is normally a focus upon profitability, especially in the corporate sector. However, as public sector organizations and not-for-profit organizations adopt the concept of marketing, this need not always be the case.
More recent definitions recognize the influence of marketing upon society.