Planck is a MKS unit of energy (expended over time to angular momentum, etc.). One Planck unit is equal to 1 joule second (J x s) or about 0.7375 foot pound second (ft x lb x s). Atomic nuclei possess an intrinsic angular momentum referred to as spin, measured in multiples of Planck's constant. The unit is named for the German physicist Max Planck.

(EMR) Electromagnetic radiation consists of an electric and a magnetic field component. All EMR travels in a vacuum at the speed of light. EMR is classified related to the frequency//length of the wave.
An EM wave consists of discrete packets of energy, named photons (quantization). The energy of the photons depends on the frequency of the wave. Planck-Einstein equation:
E = h * f
E (energy); h (Planck's constant); f (frequency)
EMR types include in order of increasing frequency//decreasing wavelength: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays and gamma rays. EMR contains energy and momentum, which may be imparted when it interacts with matter.

See Gamma Radiation.

The energy of a photon is direct proportional to its frequency.
E = h * v
E = Energy (J joule)
h = Planck's constant, 6.626 x 10^-34 J-s (Joule-seconds)
v = Frequency (Hz)
This relation between energy and frequency of a photon is known as Planck's relation.

See also Photon.

Quantum is a discrete and the smallest natural unit of energy and momentum. Planck makes the assumption that every energy transfer on a sub-atomic level consist of small units, called quanta. The view of electromagnetic energy as photons reflects this quantization.
E = h x v
E = energy
h = Planck quantum of action = 6.6261 x 10^-27 erg sec
v = frequency.