≈80% of lending in financial markets is collateral-based
financial institutions use government bonds as collateral for short-term loans
you're using immovable property as collateral for a generally longer term-loan
real estate is a great asset because banks lend ≈75% of its value
so if your property is worth $100K, you can borrow $75K against it at a low rate
the immovable property is used as collateral