The core structure of the Babylon Protocol is the Babylon blockchain, which is a POS blockchain built on the Cosmos SDK and compatible with Cosmos IBC. It enables data aggregation and communication between the Bitcoin chain and other Cosmos application chains. Users can lock Bitcoin on the Bitcoin network to provide security for other POS consumption chains while earning staking rewards. Babylon allows Bitcoin to leverage its unique security and decentralization features to provide economic security for other POS chains.