How are somaclones cultured from explants in vitro conditions?

How are somaclones cultured from explants in vitro conditions? Why are somaclones so called?

The explant from the plant is grown in a culture medium which is rich in inorganic nutrient, vitamins and growth regulators such as auxins and cytokinins. This method of producing plants through tissue culture is called micropropagation.

The plants produced from the original plant are genetically identical, so they are called somaclones.