Infrared radiation is a form of electromagnetic radiation that falls between visible light and microwave radiation on the electromagnetic spectrum. It has longer wavelengths than visible light, ranging from about 700 nanometers to 1 millimeter.
Sunlight: The sun is a natural source of infrared radiation, with a significant portion of its energy emitted in the infrared range.
Heat from Objects: All objects with a temperature above absolute zero emit infrared radiation. This is the basis for thermal imaging and heat detection.
Artificial Sources: Infrared lamps, heaters, and other devices are designed to produce and emit infrared radiation for specific purposes.