Here's a concrete example. AAVE is a protocol that allows lenders to lend money to borrowers in a decentralized manner.
So as a borrower, today, if you were to borrower 8000 USDC and deposit 10 ETH as collateral, the AAVE protocol would automatically sell your collateral if the ETH price went to 941$. So your position is "auto liquidated". https://aavecalculator.com/
AAVE currently has ~$9.9B in assets locked into its protocol.