Individual Cadaobjeto then is created on the basis of what it is defined naclasse. For example, homo sapiens is a mammal classroom; each individual serhumano is one object of this classe.’ ‘ Objects identical deestrutura and behavior are described as belonging auma classroom, in such a way that the description of its properties can serfeita of one alone time, of concise, independent form of the number deobjetos identical in terms of structure and behavior that to possamexistir in an application. The notion of an object is aoconceito equivalent of an 0 variable in conventional programming, therefore especificauma storage area, whereas the classroom is seen as a tipoabstrato of data, a time that the definition of a type represents.Each object created from a classroom is called of instnciadessa classroom. A classroom to provide all the information necessary to paraconstruir and to use objects of a type, each instance umaclasse belongs it and a classroom can possess multiple instances. Had to fatode all the instances of a classroom to share the mesmasoperaes, any difference of answers the accepted messages porelas, are determined by the values of the instance 0 variable. Figure 2.
Relationship between classrooms and objects Figure 2. illustrates the relationship between classrooms and objects. Cadaobjeto instanciado from a classroom possesss the defined properties ecomportamento in the classroom, in the same way that a varivelincorpora the characteristics of its type. The existence of classesproporciona a profit in reusabilidade. therefore the code of the operations and aespecificao of the structure of a potentially infinite number deobjetos are defined in an only place, the classroom. Each time that umnovo object is instanciado or that a message is sent, the definition daclasse is reused.
In case that classrooms did not exist, for each novoobjeto servant, would be necessary a complete definition of the object. Metaclasses One metaclasse is a classroom of classrooms.