The following text will give a brief introduction to the physics of the spatially ordered structures, so-called Coulomb crystals, that appear when confined ions are cooled to sufficiently low temperatures. It will as well briefly comment on the very diverse scientific applications of such crystals, which have emerged in the past two decades. While this document lacks figures, it includes a substantial number of references in which more detailed information can be found. It is our hope that the text will stimulate the readers to dig deeper into one or more of the discussed subjects, and inspire them to think about new potential applications.