Instead of having an "instance" of an object that is based on some "class", in Self one makes a copy of an existing object, and changes it. So codice_2 would be created by making a copy of an existing "Vehicle" object, and then adding the "drive fast" method, modelling the fact that it happens to be a Porsche 911. Basic objects that are used primarily to make copies are known as "prototypes". This technique is claimed to greatly simplify dynamism. If an existing object (or set of objects) proves to be an inadequate model, a programmer may simply create a modified object with the correct behavior, and use that instead. Code which uses the existing objects is not changed.