Consumer Behavior is the study of how individuals make decisions to spend their available resources (time, money, effort) on consumption related items.
It is the study of consumers and the processes they use to choose, use (consume), and dispose of products and services. A more in depth definition will also include how that process impacts the world. Consumer behavior incorporates ideas from several sciences including psychology, biology, chemistry and economics.
"All marketing decisions are based on assumptions
and knowledge of consumer behavior,"