It is anything that will increase your wealth without personal labor.
- Businesses. This is a broad asset class. You can buy dividend-stocks on the market, and then the companies will pay you a share of the profit. You can start your own business. You can buy into other private businesses.
- Bonds. When you invest in bonds, you collect interest just like your bank is collecting on a mortgage.
- Books. A good book will generate cash for a long time.
Assets that don't generate cash, but might increase in value.
- Land. A piece of land generates cash when you rent or lease it.
- Collectibles such as art or watches.