Aakash Deep

sensor faucet (also known as a touchless, automatic, or hands-free faucet) is a plumbing fixture equipped with a sensor and mechanism that allows water to flow in response to the presence of a hand or object, without the need to turn a handle. 
They are standard in public restrooms (airports, malls) but are becoming increasingly popular in modern residential homes. Here is a detailed breakdown of how they work, their components,