This chapter is a review of the literature published between June 2013 and May 2014 on physical and theoretical aspects of nuclear magnetic shielding. Theoretical aspects include (a) general theory, for example, newly developed approaches in relativistic theory of nuclear shielding, the relation between the spin-rotation tensor and shielding in relativistic theory, NMR shielding for electronically degenerate states and benchmark studies (b) ab initio and DFT calculations, both relativistic and non-relativistic. Physical aspects include (a) anisotropy of the shielding tensor, (b) shielding surfaces and rovibrational averaging, (c) isotope shifts, (d) intermolecular effects on nuclear shielding, and (e) absolute shielding scales.