Fluid (by Instadapp) is an isolated-vault lending protocol. Each position lives in its own vault with its own risk parameters.
Unlike Aave's cross-collateral account, each Fluid vault is a separate collateral/debt pair. A drop in one vault does not affect another.
Fluid computes a ratio per vault from supply, oracle price and the vault's liquidation threshold. Below 1.0 the vault becomes liquidatable.
LendGuard reads Fluid positions via the VaultResolver contract on Ethereum, Arbitrum, Base, BNB Chain, Polygon and Plasma.
Aave pools all your collateral and debt into one account-wide health factor; Fluid keeps each vault independent. You can check both with LendGuard.