Plain meaning
Start with the shortest useful explanation before going deeper.
The ability of different blockchains to communicate and share data or assets. Achieved through bridges (Wormhole), messaging protocols (LayerZero, Axelar), and shared standards. Cross-chain interoperability enables multi-chain DeFi, unified liquidity, and chain-agnostic applications. Solana connects to other chains primarily through Wormhole and Circle's CCTP.