Coulomb gases are special probability distributions, related to potential theory, that appear at many places in pure and applied mathematics and physics. In these short expository notes, we focus on some models, ideas, and structures. We present briefly selected mathematical aspects, mostly related to exact solvability, and to first and second order global asymptotics. A particular attention is devoted to two-dimensional exactly solvable models of random matrix theory such as the Ginibre model. Thematically, these notes lie between probability theory, mathematical analysis, and statistical physics, and aim to be very accessible. They form a contribution to a volume of the "Panoramas et Synthèses" series around the workshop "États de la recherche en mécanique statistique", organized by Société Mathématique de France, held at Institut Henri Poincaré, Paris, in the fall of 2018 (https://statmech2018.sciencesconf.org).