供緊摟 Property under Mortgage loan.
It is an asset as you own the property.
It is a liability as you have to pay the mortgage loan from the bank.
If the value of the property if lower than the bank loan, you have an excess payment to the bank even you sell out the property. So, in this case, you have a liability.
And, of cousre, you have more money ( Wealth ) if the value of the property is much higher than the outstanding mortgage loan, an asset of you.