What do we mean by decantation process?
Decantation is a process in which a mixture of solid and liquid or two immiscible liquids is left undisturbed. This is to allow the denser liquid or insoluble solid components to settle by gravity. Once the mixture components have separated, the lighter liquid is poured off leaving the denser liquid or insoluble solids behind.
For eg: Before cooking rice in the rice cooker, first, you wash the rice pellets in water and then pour out the water. The act of pouring the water from the container is decantation. We are separating water/ liquid from an insoluble solid (rice). The water poured out is called a supernatant liquid and the insoluble solids left are the sediments.