Okay kiddo, have you ever seen some plants growing in your yard or garden that you don't like? Maybe they're weeds, and they look different from the plants you actually want to grow. Well, sometimes those weeds can start growing before the plants you want, and they can take over your whole yard or garden!
That's where something called a "preemergent herbicide" comes in. A herbicide is a chemical that can kill plants, and preemergent means it works before the plants have even started growing yet. So, when you use a preemergent herbicide, you're putting down a sort of invisible barrier in your soil that stops the weed plants from being able to grow in the first place.
It's like putting up a fence to keep your neighbor's cat out of your garden - except in this case, the "fence" is made of special chemicals that only kill the plant seeds that are trying to grow. Don't worry, though, it won't harm the ground or the other plants you want to grow - it only affects the weed seeds.
So, by using a preemergent herbicide, you can make sure your garden or yard stays beautiful and free of those pesky weeds that try to take over everything. Pretty cool, huh?