Consumer helps answer questions such as why people choose one product or brand over another

The answer is Consumer Behavior

Explanation:

Consumer Behavior is the study of individual customers, a group of people or organizations with regard to how these people and organizations purchase and dispose goods and services that are needed to satisfy their wants or needs.

This study seeks to understand how the behave in  the marketplace and the reason(s) for this behavior.

The importance of understanding consumer behavior is that it can help you become more effective at marketing, advertising, product design and development, which will have the major impact of your customers.

An example can be seen when someone seeks the advice of his/her friend before purchasing a car. In this case, they may buy the car not because they like it, but because a friend recommended that car.