[en] In this lecture, I would like to present part of the experimental data measured in Relativistic Heavy Ion experiments. The main goal of RHIC experiments is to extract information on the properties of the hot and dense nuclear matter drop that has been created during non-peripheral collisions of two nuclei. As this task in itself raises several important questions, we shall discuss them in the introductory part. In the second part, we shall describe the first type of experimental results that were obtained in the field: inclusive and correlation data. Finally, in the third part, we shall review some of the pion production data (above threshold)