The electromagnetic spectrum ranges from the short wavelength gamma rays all the way upto the long wavelength radio waves. Shorter the wavelength, greater will be the energy of radiation as per the equation
E = hc/λ
where E = energy, h = Planck's constant, c = speed of light and λ = wavelength
Therefore, from the largest to the shortest the order would be:
Radio wave
Microwave
Infra red
Red visible
Orange visible
Yellow visible
Green visible
Blue visible
violet visible
Ultraviolet
X-ray
Gamma radiation