The electromagnetic spectrum refers to the entire range of electromagnetic radiation. Electromagnetic radiation travels through space at the speed of light, and is characterized by both its wavelength and frequency.
The electromagnetic spectrum is typically divided into different regions, based on the wavelength or frequency of the radiation. These regions, in order of increasing frequency and decreasing wavelength, include:
Radio waves: These have the longest wavelength and lowest frequency in the electromagnetic spectrum, and are used for communication, such as in radio and television broadcasting.
Microwaves: These have shorter wavelengths and higher frequencies than radio waves, and are used for communication, as well as in microwave ovens and in scientific research.
Infrared radiation: This has wavelengths shorter than microwaves, and is often associated with heat. Infrared radiation is used in thermal imaging cameras, as well as in remote controls and sensors.
Visible light: This is the portion of the electromagnetic spectrum that is visible to the human eye. It includes the colors of the rainbow, from violet to red.
Ultraviolet radiation: This has shorter wavelengths and higher frequencies than visible light, and can be harmful to living organisms in high doses. Ultraviolet radiation is used in medical treatments, such as for skin conditions.
X-rays: These have even shorter wavelengths and higher frequencies than ultraviolet radiation, and are used in medical imaging and radiation therapy.
Gamma rays: These have the shortest wavelengths and highest frequencies in the electromagnetic spectrum, and are often associated with nuclear radiation. Gamma rays are used in medical imaging, as well as in scientific research.