Herbicide is a chemical substance used to kill or inhibit the growth of unwanted plants, commonly referred to as weeds. Herbicides are an essential tool in agriculture, landscaping, and gardening to manage weed populations and prevent them from competing with desired crops or plants. There are selective herbicides, which target specific types of weeds, and non-selective herbicides, which kill most plants they come into contact with. Careful application is important to avoid harming nearby plants.