What is income?

The flow of money to the factors of production : WAGES to LABOUR; PROFIT to ENTERPRISE and CAPITAL; INTEREST also to capital; RENT to LAND. Wages left for spending after paying taxes is known as disposable INCOME.
The return in money from one’s business, labor, or capital invested; gains, profits, salary, wages, etc. The gain derived from capital, from labor or effort, or both combined, including profit or gain through sale or conversion of capital.