Explain How a Yield-Bearing Token Is an Example of DeFi Composability

A yield-bearing token is a token (e.g. cETH or a-USDC) that represents a deposit in a lending protocol and automatically accrues interest. It is an example of composability because this token, while representing a debt position, is also an ERC-20 token that can be used in other DeFi protocols.

For instance, a user can deposit USDC into a lending protocol to get a-USDC, then use that a-USDC as collateral in a derivative platform or deposit it into a yield farming vault, stacking multiple financial operations.