Define NPK fertilizer. Why is NPK fertilizer called a complete fertilizer?

Explanation:

NPK fertilizer is the nitrogen, phosphorus and potassium fertilizer use on the soil to add nutrients to it which boost plants growth, The N stand for nitrogen, P for phosphorus and the k for potassium.

NPK is refer to as complete fertilizer because it contain the complete ratio or amount of Nitrogen, phosphorus and potassium in it. These three elements are very essential nutrients that increase soil fertility, without any of these elements present it will affect the soil and the plants growth will also be altered.