According to the American Marketing Association;

Marketing is the activity, set of institutions, and processes for creating, communicating, delivering, and exchanging offerings that have value for customers, clients, partners, and society at large.

According to Wikipedia;

Marketing refers to activities a company undertakes to promote the buying or selling of a product, service, or good.

According to NYT;

Marketing is the art of telling stories so enthralling that people lose track of their wallets.

According to Britannica;

Marketing, the sum of activities involved in directing the flow of goods and services from producers to consumers.

According to Dictionary.com;

The action or business of promoting and selling products or services, including market research and advertising.