Udemy is an online platform that lets its user take video courses on a wide array of subjects. Instead of being a consumer on Udemy you can instead be a producer, create your own video course, and allow users to purchase it. This is a fantastic option if you are highly knowledgeable in a specific subject matter. This can also be a great way to turn traditional tutoring into a passive income stream!
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.