What is a Fertilizer? A Fertilizer is a material that is added to the soil to supply one or more elements required for plant growth and productiveness. The major three elements are nitrogen, potassium and phosphorus, the secondary elements are calcium, sulfur, magnesium, and other elements. Fertilizers enhance the natural fertility of the soil.

There are broadly 2 types of Fertilizers.
Organic fertilizers include properly managed manure and compost.
Whereas, Inorganic fertilizers, also known as Artificial fertilizers, are formulated in appropriate concentrations and combinations supply three main nutrients: nitrogen, phosphorus and potassium that is, N, P and K, Hence they are named as NPK fertilizers.

The one Here, on left hand side, white colored salt is plain urea salt, which we are not going to use it for our home garden, because it has very high nitrogen content of above 80% which can burn the plant and roots, if used in higher quantity.

The other one, creamy yellowish crystals here are NPK fertilizer. We usually use percentages of 20 20 20 combination of NPK. Hence its also called as NPK 20-20-20.

N – the nitrogen, promotes leaf growth and forms proteins and chlorophyll. P – the phosphorus, contributes to root, flower and fruit development. K – the potassium, contributes to stem and root growth and the synthesis of proteins.