If you’d like to discover what lies behind the term “nanoparticles,” please come to the conference taking place at the Popular University of Philosophy on Friday, January 16th.Nanoparticles are experiencing a boom due to the novel properties that can emerge at these nanometric sizes. After a general introduction, I will present how to synthesize nanoparticles and detail their uses in applications ranging from catalysis to the fabrication of new magnetic materials.