Nuclear magnetic resonance (NMR) has undergone a revolution in the last decade with the original slow-passage spectroscopy method being replaced by pulsed methods. Much of pulsed NMR can be understood in terms of a simple classical, or semi-classical, model of precessing spin vectors, but some new techniques are based purely on quantum mechanical physics. One very useful technique described in this paper is the DEPT sequence, which is an example of correlated quantum states of the type invoked in the Einstein, Podolsky and Rosen paradox. These new developments are not only exciting because of their potential applications, but also interesting in terms of their underlying physics.