High Temperature Superconductivity in the Cuprates: Phenomena from a Theorist's Point of View

I present a selection of experimental results on metallic cuprates, both above the superconducting transition temperature $T_c$ (often called the strange metal state) and in the superconducting state. It highlights this still poorly understood part of the physical world. After an introduction, I talk briefly about the pseudogap regime and about the unusual linear resistivity phenomenon. Several empirical correlations between observed quantities are mentioned, e.g. $T_c$ and superfluid density (Uemura), $T_c$ and next nearest neighbour hopping, slope of the linear resistivity and $T_c$. In the belief that a comprehensive explanation may need an understanding of the extremely strongly correlated metal, a few initial steps in this direction are outlined.