|Résumé||This tutorial offers some insight into the question ``What is quantum chaos and why is it interesting?''. Its main purpose is to present some signatures of chaos in the quantum world. This is ıt not} a technical reference, it contains but a few simple equations and no explicit references; rather, the main body of this manuscript is followed by a reading guide. Some of the mathematical tools used in the field are so cumbersome they often obscure the physical relevance of the problem under investigation. However, after having consulted this tutorial, the technical literature should appear less mysterious and, we hope, one should have a better intuition of what is interesting, and what is superficial!