How does infrared radiation occur? where and how is it accounted for and used?

How does infrared radiation occur? where and how is it accounted for and used? Is it radiated by the objects around you and why?

In heated objects, infrared radiation is generated, also called “thermal radiation”, because felt by a person as warmth. It is widely used: 1) military equipment: – missile guidance, – night vision devices, etc .; 2) civil engineering: – fiber-optic communication devices; 3) medicine: – determination of the pulse rate, – characteristics of blood flows, – blood oxygen saturation, – physiotherapy; 4) industry: drying of painted surfaces, – sterilization of food products, – conveyor drying conveyors when laying grain for storage and the flour-grinding industry; 5) cash settlements for checking money; 6) astrophysics and astronomy: – devices for studying space objects, visible in infrared radiation; 7) electronics: – communication of systems with peripheral devices, – automation systems, – security devices, – mobile phones, etc. Many things, widely used by us, produce IR radiation: – an incandescent lamp and a gas-discharge lamp, – about 50% of the radiation from the Sun – is IR; some lasers emit it. It is determined using thermal and photoelectric detectors, and special photographic materials.