The modern definition of the economy and the economics varies widely. The subject itself is evolving every day along the opposing views among economists. Throughout the time as civilization progressed economic conditions changed as well. As a result, the definition of economics also evolved. Modern economic theory looks beyond goods as simply the source of production and beyond the classic invisible hand theory; it also examines the role of demand, money supply, and other behavioral factors that affect growth. Throughout the history of economic thought, human was considered as Homo economicus, formulation of the Homo sapiens which portrays humans as consistently rational and self-interested subjects that always maximize utility for themselves. When talking about financial markets the theory of the efficient market hypothesis states that the prices of financial assets are reflected by the available information. On the other hand, some economists noticed that financial markets are often irrational. This is the starting point of behavioral finances which use psychology and sociology to explain the divergence in financial markets from the predictions of the efficient market hypothesis. Behavioral finance are posed to explain people's actions, whereas modern finance seeks to explain the actions of the "economic man" (Homo economicus). The role and significance of behavioral economics continue to provide better insights into the real motives of human behavior in the uncertain economic environment. The failure of economics to address the challenges of predicting and preventing crises questions the reliability of traditional economic hypotheses. This poses another problem - if economic decisions are made based on inadequate theories, actions can bring unexpected consequences. In today's world, the behavioral approach offers wider explanations of human decisions and macroeconomic processes.