A lot of things :D, ive covered a few in my answer below but can contribute more and an better explination if you want anything specific.
All Electromagnetic radiation lies on a spectrum. At the low energy end you have radio waves and at the high energy end you have gamma rays.
The electromagnetic spectrum goes:
All electromagnetic waves also share a relationship between their wavelength and frequency and with the speed of light. This is shown by the equation
#c= λ "(wavelength)" xx v "(frequency)"#
As the speed of light is a constant
The final point is all electromagnetic radiation produces an electric field and a magnetic field. The electric field lies in a plane which is perpendicular to the direction of travel of the magnetic field. The picture below shows this:
I hope this highlights a small number of the relationships between the different types of electromagnetic radiation.