What is the main purpose of marketing? Can marketing manipulate customers want and create new needs for the customer or satisfy the needs and wants? Why?

Marketing basically consists of buying, selling of goods and services including market research, promotion and advertisements. It's purpose is to identify the needs and wants of customers, to satisfy them and to convince the buyers to purchase goods and services.

Yes, promotion and advertising plays a vital role in manipulating customers to acquire new wants, as it is said wants are unlimited, so with the advancement of technology every now and then the products keeps on updating its features which lures the customers to convert their wants into their needs. Some of the examples are smart phones and automobiles. 

Marketing is the ability to convince people to buy your product, to make the rank and position of the company higher, and to generate leads.

Manipulating customers is a very normal behavior of the marketing departments, convincing them their life is not complete without your product/service, let's take Apple for example, they portrait smart phones as the following : if you don't have an Iphone you do not have a smart phone, although there'r multiple mobile companies as good and maybe better than apple.