The document discusses the electromagnetic spectrum, which is the range of different types of electromagnetic radiation. It notes that electromagnetic radiation includes visible light, radio waves, microwaves, infrared, ultraviolet, X-rays and gamma rays. These different types of electromagnetic radiation are classified based on their frequency and wavelength, with radio waves having the lowest frequency and longest wavelengths, and gamma rays having the highest frequency and shortest wavelengths. The document also provides some examples of applications of these different types of electromagnetic radiation, such as using radio waves for telecommunications, microwaves for heating food in ovens, infrared for remote controls, and X-rays and gamma rays for medical applications.
![Electromagnetic Spectrum ( Introduction ) ,[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)