Passive income is money you make off an investment without having to do anything after the initial setup.
The idea that you are not actively involved in managing the investment is an important one because there are a lot of scams and schemes out there in passive income clothing.
It doesn't take more than five minutes online to see one of these `great opportunities'. Much of the time, the only person making passive income is the guy selling his strategy to others.
While true passive income is the Holy Grail for investors, few investments offer income returns with no involvement by the investor.