Marketing-"taking actions to define, create, grow, develop, maintain, defend and own markets".
An approach to business that seeks to identify, anticipate and satisfy customers needs.[1]
Al Ries and Jack Trout defined marketing as simply "war" between competitors.
At a macro level, marketing is the process of raising the standards of living, by identifying the existing problems and unsatisfied needs of people and then satisfying that need with a product/service that delivers value to the customer.
References
↑ "What Is Marketing?" from marketingprofs.com [1]