Micro foucus on individual behavior: there are two major player in the microeconomic studies. The consumer and the firm. Most of the time they can be study with similar method, that's why some text book begin with the consumer behavior and others with firms' behaviour. To study there behaviour we need to understand their preference, objectives, and constraints. Given these three major theme, we will be able to derive the demand and supply decisions for these firms. Then we move on to study the factors that affect the demand and supply of the consumers and firms. Build up on this foundations, we will study how different assumptions that we made during the derivation of supply and demand relation will affect the outcome. Then we will move on to study the general equilibrium where all market are in equilibrium and how different market intefere with each other. With the emerging of game theory, we have a new perpectives to study microeconomics, we can view decisions as a strategice outcome, where people or fimr's decisions are interdependent. This gives us the opportunity to forecast and predict the future behavior and more robust interpretation than the pure optimisation problems which based on a lot of strong assumptions.