Advances in nanotechnology have allowed physicists and engineers to miniaturize electronic structures to the limit where finite‎-size related phenomena start to impact their properties‎.‎ This book discusses such phenomena and models made for their description‎.‎ The book starts from the semiclassical description of nonequilibrium effects‎,‎ details the scattering theory used for quantum transport calculations‎,‎ and explains the main interference effects‎.‎ It also describes how to treat fluctuations and correlations‎,‎ how interactions affect transport through small islands‎,‎ and how superconductivity modifies these effects‎.‎ The last two chapters describe new emerging fields related with graphene and nanoelectromechanics‎.‎ The focus of the book is on the phenomena rather than formalism‎,‎ but the book still explains in detail the main models constructed for these phenomena‎.‎ It also introduces a number of electronic devices‎,‎ including the single‎-electron transistor‎,‎ the superconducting tunnel junction refrigerator‎,‎ and the supercond‎.‎‎.‎‎.‎