Okay kiddo, have you ever seen a garden or a park full of plants and trees? Sometimes, people use special chemicals to kill weed, or unwanted plants that are growing in the wrong places. This is called herbicide.
Now, imagine if someone wanted to hurt or kill people by using these chemicals on a large scale. This is called herbicidal warfare, which is a form of chemical warfare. In war, one country or group may use herbicides to destroy crops, forests, or simply to wipe out an enemy's food source.
It's not a good thing, buddy. Herbicidal warfare can cause harm to people, animals, and the environment. It's important for countries to agree not to use these chemicals in harmful ways, except for strictly controlled, civilian and agriculture purposes. And let's hope that people in power make those right decisions, so we can all enjoy our green spaces without being worried or harmed.