Purport

This is one of the very important Shlokas. This shloka removes one of the biggest misconceptions about Hinduism.

The existing caste system is one of the biggest arguments which is used against Hinduism. Contrary to what is believed and propagated, Srimad Bhagvad Gita clearly declares that Varnas are based upon the actions and internal nature of a human. There are three different modes of the material world the Sattva, Rajasa, and Tamasa. These Gunas are present in different proportion in human. Based on that human possess a specific nature and develops specific skills. The same is classified into four types which are known as Varnas.

"Peacefulness, self-restraint, austerity, purity, forgiveness, simplicity, knowledge, specialized knowledge and with belief in God are the duties born of the nature of Brahamans;"(18:42)
"Heroism, effulgence, courage, not feeling from battle, generosity, and leadership are the duties born of the nature of Kshatriyas(Warrior class)."
"Agriculture, Farming, cow herding, and doing business world-wide are the duties born of the nature of the Vaishyas.

Those who cannot possess any of the skills are incapable of doing anything engage in doing physical work, they are Shudras.

Such divisions are natural and found in every organization, where different departments like engineering, account, sales, marketing, etc created based upon the task performed. Varnas are similar classification of society.