Bridges serve as connectors between two distinct blockchain ecosystems, facilitating asset transfers and data transactions. There are several types of bridges: 1. **Trusted Bridges**: These require users to trust an intermediary party or consortium that manages cross-chain transactions securely. 2. **Trustless Bridges**: Utilizing cryptographic proofs like zero-knowledge proofs or inter-blockchain communication protocols (IBC), they allow secure transactions without needing trust in a third party. 3. **Liquidity Networks**: By locking assets into smart contract-based liquidity pools on one chain, equivalent tokens can be minted on another chain representing those assets. 4. **Relay Chains**: Relay chains act as intermediaries connecting multiple parachains (independent chains) within a network like Polkadot. They facilitate communication and interoperability between these parachains.