Consumer Choice Theory explains how individuals make decisions about purchasing goods and services based on their preferences and budget constraints. It suggests that consumers aim to maximize their satisfaction or utility by choosing combinations of products that provide the most value within their financial limits. This theory also considers factors like substitutes and complements, which influence consumer decisions. For example, if the price of a substitute good decreases, consumers may shift their purchases away from the more expensive option. Understanding these choices helps businesses and policymakers predict market behavior and design effective strategies.