I. Universality and the RG

The basic ideas of critical phenomena theory including Universality and Scaling are Reviewed. These are tied up in a neat package via the Renormalization Group idea a la K. W. Wilson. This method is described in one concrete example, its application to Ising models. A formalism for renormalization is set up. The concept of a fixed point is explored and shown to give rise to behaviors described by the words "scaling" and "universality" as well as "relevant", "marginal", and "irrelevant". An explicit example of an approximate renormalization scheme is developed using "lower bound" approximation techniques.