The spectrum of all possible frequencies of electromagnetic radiation is called the electromagnetic spectrum. This spectrum includes various types of radiation, ranging from radio waves with long wavelengths to gamma rays with very short wavelengths. The electromagnetic spectrum encompasses visible light, which is the portion detectable by the human eye, as well as infrared, ultraviolet, X-rays, and microwaves. Understanding this spectrum is essential in fields like astronomy, telecommunications, and medical imaging, as it provides insights into the behavior and properties of electromagnetic radiation.