Index funds provide you with a way to invest in the stock market that is completely passive. For example, if you invest money in an index fund that is based on the S&P 500 Index, you will be invested in the general market, without having to concern yourself with choosing investments, rebalancing your portfolio, or knowing when to sell or buy individual companies. All that will be handled by the fund which will base the fund portfolio on the makeup of the underlying index.
With 1.27 billion people and the world's third-largest economy in terms of purchasing power, India's recent growth and development has been one of the most significant achievements of our times. Over the six and half decades since independence, the country has brought about a landmark agricultural revolution that has transformed the nation from chronic dependence on grain imports into a global agricultural powerhouse that is now a net exporter of food. Life expectancy has more than doubled, literacy rates have quadrupled, health conditions have improved. India will soon have the largest and youngest workforce the world has ever seen. At the same time, the country is in the midst of a massive wave of urbanization as some 10 million people move to towns and cities each year in search of jobs and opportunity. It is the largest rural-urban migration of this century. Massive investments will be needed to create the jobs, housing, and infrastructure to meet soaring aspirations and make towns and cities more livable and green.
For a person working for a wage, their source of income is their job, or their labor (aka their time that they sell to someone). But you can own a house, and rent it out, and when your renters pay you renter every month, the source of that income check is your rental property, or your house. It would just be called rental income. If you have money in the bank in an account that pays interest, those interest payments are another source of income. We can say the source is interest payments, or we can identify the asset that is generating rent, and say your money in the bank that is generating “rent” (aka interest) is your source of income.