Asset types

What you can own.

The main ones

Shares are ownership. Bonds are loans. Property is a physical asset with rent and costs. Cash is safety. Commodities and currencies produce nothing and rely entirely on price moves.

Bond holders are paid before shareholders in a failure, which is why they earn less.
Anything producing no income depends purely on someone paying more later.

Funds

A fund pools money to buy many holdings at once. An index fund holds everything in a market segment and charges very little, because it makes no selections.