Plant fertilizers are substances added to soil or plants to provide essential nutrients that promote growth. They typically contain key elements like nitrogen, phosphorus, and potassium, which are crucial for plant health. Fertilizers can be organic, derived from natural sources like compost or manure, or synthetic, made from chemical processes. Using fertilizers helps improve soil fertility and can lead to higher crop yields. However, it's important to apply them correctly to avoid over-fertilization, which can harm plants and the environment. Proper understanding of soil types and plant needs is essential for effective fertilizer use.