The aim of this survey, written by V. A. lskovskikh and Yu. G.Prokhorov, is to provide an exposition of the structure theory of Fano varieties, i.e. algebraic varieties with an ample anticanonical divisor.Such varieties naturally appear in the birational classification of varieties of negative Kodaira dimension, and they are very close to rational ones. This EMS volume covers different approaches to the classification of Fano varieties such as the classical Fanolskovskikh"double projection"metho