Science is a form to arrive at the scientific knowledge, that has a method (it distinguishes it to this of the rest of the knowledge forms), whose essence it is the hypothesis contrast; therefore, so that a hypothesis is scientist must be susceptible to be falsified. One of the main elements that distinguish to the scientific knowledge of the other knowledge, is " Mtodo" (joint of rules accepted by the scientific community). The scientific knowledge is hypothesis and contrast. Factual sciences that is to say: Biology, sociology, history, the physics, chemistry, needs the observation and the experimentation. They are based on the reality of the facts. The falsacin occurs in the reality. Formal sciences like mathematical and the logic, do not need experimentation because they occur to rational level. The falsacin occurs in the reasoning. Characteristics of " Cientfico&quot knowledge;: 1) must be " Racional" ; science is a set of ideas; 2) it must be " Objetivo" , it tries to verify the ideas that we have of the facts; 3) " hechos&quot extends; , part of the thickness of the facts discards the facts that are superfluous; it selects those that think that they are excellent, explains in terms of laws and theories; 4) " Analtico" , it disturbs the reality in parts, it distinguishes his different parts; 5) " Especializada" , one specializes in different parts from the reality; 6) " Claro and Preciso" ; he is not vague nor superficial; 7) " Contrastable" , the mechanisms of the contrast are: the verification or the verification; it must formulate a hypothesis and to look for its verification or verification and the falsacin must formulate a hypothesis and try to falsify it; " Comunicable" , it is possible to be expressed and to be made arrive at the others; 9) " Metdico" , it is glided and coherent; 10) " General" , the generalization tries towards the set; 11) " Legal" , it tries to structure laws; 12) " Explicativa" , why and how? , the phenomena happen; 13) " Predice" , it can act on the reality; 14) " Abierto" , always it is in the hope of new things that to perhaps demonstrate us, that what until now is correct no longer is it.