Gushel-Mukai varieties are smooth (complex) dimensionally transverse intersections of a cone over the Grassmannian Gr(2,5) with a linear space and a quadratic hypersurface. They occur in each dimension 1 through 6 and they are Fano varieties (their anticanonical bundle is ample) in dimensions 3, 4, 5, and 6... The aim of this survey is to discuss the geometry, moduli, Hodge structures, and categorical aspects of these varieties. It is based on joint work with Alexander Kuznetsov and earlier work of Logachev, Iliev, Manivel, O'Grady, and Perry. (read more)