Recent definitions of marketing place more emphasis on the consumer relationship, as opposed to a pure exchange process. For instance, prolific marketing author and educator, Philip Kotler has evolved his definition of marketing. In 1980, he defined marketing as "satisfying needs and wants through an exchange process", and in 2018 defined it as "the process by which companies engage customers, build strong customer relationships, and create customer value in order to capture value from customers in return". A related definition, from the sales process engineering perspective, defines marketing as "a set of processes that are interconnected and interdependent with other functions of a business aimed at achieving customer interest and satisfaction".