Black money is a term that's used to refer to any income which is earned through illegal means or as a result of tax fraud. There is no one consensus on how to quantify or measure black money, but generally it's associated with any transaction that has not been properly recorded in the legitimate economy.

Black money can be earned through a variety of activities, including illegal or unreported work, smuggling and drug trafficking. Often the income is illegally disguised as well, through the use of money laundering, which is used to obscure the source of the illegal funds and make it appear to be legitimate. Other methods of disguising black money include the use of falsified documents, hiding it in offshore accounts, investing it in foreign stock markets and more.

The presence of a higher amount of black money in the economy is of great concern, as it can have significant negative effects, including increased levels of corruption. For example, individuals and businesses that have access to a large accumulation of black money may be able to bribe public officials or pay them off in exchange for special favors or contracts. This can lead to an unfair advantage in the market and skew the competitive landscape.

On the other hand, black money can also be beneficial in some cases. For example, in countries with oppressive laws or restrictions on certain activities, there may be an incentive to use black money to bypass those laws and engage in activities that would otherwise be prohibited. This can help promote economic freedom and provide a way for people to improve their economic situation.

Overall, black money is a very dangerous phenomenon that can have a great deal of negative implications for society. It can lead to increased corruption at the highest levels of government and can potentially distort free markets. Although it may have some beneficial uses, it is generally advisable to avoid any activities that result in the growth of black money and make sure to report any suspicious transactions to the authorities.