Infrared rays are a type of electromagnetic radiation that have longer wavelengths than visible light. Infrared rays are not visible to the naked eye, but can be detected using special equipment such as infrared cameras.

Infrared radiation is emitted by all objects with a temperature above absolute zero and can be used for various purposes such as heating, cooking and communication. It is also commonly used in medical imaging, security systems and environmental monitoring.

The human body also emits infrared radiation, which is why thermal imaging cameras can detect differences in body temperature and help diagnose certain conditions.