2.1 The nature of x-rays

Radiation is the transport of energy that comes from a source and travels through a vacuum or through matter-containing media. Radiation is classified into two main categories, non-ionizing and ionizing, depending on its ability to ionize matter. Light, radio, and microwaves are types of radiation that are called non-ionizing.

X-rays are a type of electromagnetic radiation having wavelength shorter than that of the ultraviolet electromagnetic radiation and larger than that of the γ rays. At the short wavelength end, they overlap with gamma rays.