The introductory books of Economy always starts for the segmentation of the Economy in two great groups. The macroeconomic group and the microeconomic one. important to understand such differentiation even so, the two groups are strong linked. The first one, says respect to the study of the economy, in a generalized manner collective. That is, it corresponds mainly to the study of as the economic agents in accordance with act the market in an including aspect. Thus, for the Macroeconomics, to be studied field will dedicate more the questions as tax of interests, unemployment and politics among others. As the group will focar, on the other hand, in consuming the individual agents of the market Centered) Currently two economic models in use in the world exist.

The economic model of market economy and of planned economy. In the planned economies, the State is responsible for ‘ ‘ gerncia’ ‘ of the production factors. Thus, it is in charge of the State to call how much of each good it is produced and the way as this will be divided enters the diverse agents in the society. This model, in decay currently, still is used in countries as Cuba, Coreia of the north and, in particular way, in China. The market economies, on the other hand, give on the other hand freedom so that its agents decide what to produce and what to buy its necessities in accordance with. Thus, even so it has laws and regulations to be followed, the agents take the proper same decisions on the basis of itself and in what the said market. In this way, they search certain balance enters offers and existing demand of the good. Market the word market has a economic direction of a group of salesmen and purchasers who negotiate a good in question.