Residual income is when you continue to get paid after the work is done. This includes royalties from books, movies, or songs and also income that comes from real estate or business investments where you don’t actually have to be present to earn it. For example, Bill Gates is still making a residual income from Microsoft even though he isn’t working there anymore.
Passive income differs from earned income and portfolio income in a variety of ways. Passive income is generally defined as a stream of income earned with little effort, and it is referred to as progressive passive income when there is little effort needed from the individual receiving the passive income in order to grow the stream of income. Examples of passive income include rental income and any business activities in which the earner does not materially participate during the year.

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.