Uses of Sigma Models

This is a brief review of some of the uses of nonlinear sigma models. After a short general discussion touching on point particles, strings and condensed matter systems, focus is shifted to sigma models as probes of target space geometries. The relation of supersymmetric non-linear sigma models to K\"ahler, hyperk\"ahler, hyperk\"ahler with torsion and generalised K\"ahler geometries is described.
Comment: 11 pages, Corfu Summer Institute 2017 "School and Workshops on Elementary Particle Physics and Gravity" 2-28 September 2017, Corfu, Greece