Ricci solitons

English translation of “Solitony Ricciego” (Wiadomo'sci Matematyczne 48, 2012, no. 1, pp. 1-32). Despite the general-sounding title, the text covers just a few narrow topics: Perelman’s proof of the fact that compact Ricci solitons are of the gradient type, and a detailed unified description of Page’s and Berard Bergery’s Einstein manifolds on the one hand, and Koiso’s and Cao’s K"ahler-Ricci solitons on the other, as the Ricci solitons arising via conformal changes from certain special K"ahler manifolds.