Homo Economicus is a term used in economics to describe a hypothetical human being who always makes perfectly rational decisions in order to maximize their own utility (or happiness). In other words, it's an idealized version of a human being who always makes the best choices based on all available information and without any biases or emotional factors influencing their decisions. The concept of Homo Economicus is a useful way to think about economic models, but it's important to remember that it's just a theoretical construct - in the real world, human beings don't always behave perfectly rationally.