This world is a dangerous place to live, not because of the good people that often act in irrational and/or criminally wrongdoing ways within the confines of their individual minds, core or enterprise groups, but because of the good people that don’t do anything about it (like reveal the truth through education like Financial Samauri is doing!). Albert Einstein and Art Kleiner’s “Who Really Matters.”
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.