A electric glow discharge is a type of plasma formed by passing a current at 100 V to several kV through a gas at low pressure, usually argon or another noble gas. It is found in products such as fluorescent lights and plasma-screen televisions, and is used in plasma physics and analytical chemistry. A tokamak is a machine producing a toroidal magnetic field for confining a plasma which is characterised by azimuthal (rotational) symmetry and the use of a plasma-borne electric current to generate the helical component of the magnetic field necessary for stable equilibrium. It is one of several types of magnetic confinement devices, and is one of the most-researched candidates for producing controlled thermonuclear fusion power. This book discusses and presents current data on both glow discharges and tokamaks.