Passive infrared sensor

Have you ever played hide and seek with your friends and used your eyes to try and find them? Well, a passive infrared sensor (or PIR sensor for short) is kind of like having magical eyes that can see if anything warm, like a person or animal, is nearby.

Think of it like this: the sensor is like a pair of glasses that can detect heat instead of seeing things. They work by detecting changes in temperature, which means if something warm moves in front of the sensor, it will detect the change and send a signal to a computer or alarm to let you know.

But, the sensor doesn't just detect any changes in temperature. Instead, it's designed to only detect changes that are moving, because it means someone or something is nearby.

So basically, a PIR sensor is a special type of sensor that can "see" if something warm is moving nearby, like if your little brother is trying to sneak up on you during a game of hide and seek. It's like having secret superpowers!