Superconductivity in the high T_>c Oxides

Since their discovery by Bednorz and Müller [1], the high T_>c oxides have offered us the puzzle of a mix of conventional and unconventional properties both in the normal state and in the superconducting state. This is why some of the fundamental questions such as the applicability of the Fermi liquid description and BCS s-wave superconductivity are still open to discussion. Experimental results bearing on these questions will be reviewed. Special emphasis will be placed on the role played by the short coherence length in determining some of the unconventional properties of the oxides.