Laser fence

Okay, so you know how sometimes there are fences around houses and yards and other things? A laser fence is kind of like that, but instead of a physical fence made out of wood or metal, it uses lasers to make an invisible fence that can't be seen with your eyes.

The way it works is that special sensors are put in the ground or on poles and they shoot out lasers in a straight line. If anything crosses the laser line, like a person or an animal or even a leaf blowing in the wind, it breaks the lasers and that sends a signal to an alarm or something else that can let people know that something has crossed the invisible fence.

A laser fence is good because it can be easier to set up than a regular fence, and it doesn't block any views or scenery like a regular fence might. It's also easier to maintain because there are no physical components to fix or replace like there would be with a regular fence. Another benefit is that the laser fence can be adjusted so that it only detects things that are a certain height or size, so it won't accidentally set off the alarm if it's just a small animal or something.

So, that's basically what a laser fence is. It's a way to make an invisible fence using lasers to detect when things cross the line.