A reed switch is an electrical component that consists of two ferromagnetic reeds sealed in a glass tube. When a magnetic field is applied, the reeds come together, completing an electrical circuit. This allows the switch to control the flow of electricity without any physical contact, making it reliable and durable. Reed switches are commonly used in various applications, including security systems, automotive sensors, and home appliances. Their ability to operate silently and without wear makes them ideal for situations where mechanical switches may fail over time.