Given the general proposition that the pairing symmetry and T$_{c}$ are the properties of the normal state just above T$_{c}$ , the central problem for superconductivity in the Cuprates is the understanding of the nature of the quantum-critical fluctuations, which is a problem which can be usefully attempted only if the nature of Region II is understood since given the phase diagram, the fluctuations in Region I are the quantum-fluctuations of the order parameter The central organizing feature of the phase diagram is a quantum-critical point from which two lines emanate which separate the normal state in to three parts; The region of superconductivity is located around the qcp. The location of the qcp within the diagram varies with respect to the region of T$_{c}$ = 0 in different cuprates; the maximum T$_{c}$ is generally not at the doping x$_{c}$ of the qcp. In Region I, quantum-critical properties are observed in Re- sistivity, optical conductivity, Raman Scattering, nuclear relaxation rate on Cu-nuclei (but not O-nuclei which show fermi-liquid type relaxation rates), tunneling into a conventional metal and single-particle spectra measured by angle-resolved photoemission (ARPES). The superconductive pairing is in the ”d-wave” channel. The great mystery has been the nature of Region I and of Region II. Region II, the so-call pseudogap region abuts the bound- ary to Region I whose properties are determined by quantum-critical fluctuations (qcf). Through extensive experimental investigations, it is now generally believed that Region II represents a phase which competes with superconductivity, much the same as antiferromag- netism competes with superconductivity in the heavy fermions. Needless to say, Region II has no long-range anti-ferromagnetic order and near the region of maximum T$_{c}$ , in at least one of the heavily investigated Cuprates, the magnetic correlation length is about a lattice constant, which is the scale of magnetic correlations in non-interacting fermions. There have been innumerable ideas and calculations to understand the properties of the Cuprates. I will only summarize the work which seeks to understand all the principal normal state properties as well as superconductivity with one set of ideas and has predicted unique results which have been tested by experiments. This phase diagram of Fig.(11) organizes the extensive experimental investigations in the Cuprates in the last twenty years. It is the universal phase diagram in the sense that the lines drawn demarcate change in properties in the same manner in every Cuprate family investigated. (There are of-course Cuprates with special properties in one or the other re- gions of the phase diagram which are not shared by other Cuprates.) The phase-diagram is meant to be schematic and correct only in its topology. 43