Private Property can be:
A) only physical goods. You cannot own an intangible good like a patent or copyright.
B) either a tangible good like a car or land, or an intangible good like a checking account or a stock or bond.
C) can include humans as slaves according to John Locke, the philosopher of private property
D) things like navigable rivers and the oceans as long as the claim was part of original acquisition.