While residual income can be used to describe the amount of net income after all costs are paid down, it also refers to the amount of money you continue to generate after your initial work is done. There are countless ways to make money, but some are much more time-intensive than others. Active income, for example, refers to when you directly act or perform a service for money, including salaries, wages, tips, commissions, and income from a business you’re actively involved with.
Residual income is the amount of net income generated in excess of the minimum rate of return. Residual income concepts have been used in a number of contexts, including as a measurement of internal corporate performance whereby a company's management team evaluates the return generated relative to the company's minimum required return. Alternatively, in personal finance, residual income is the level of income that an individual has after the deduction of all personal debts and expenses have been paid.