Cross-chain communication refers to the ability of different Blockchain networks to exchange data and assets without any central control, evolving significantly as more and more blockchain networks are formed, each with its own unique features and capabilities.

There are several approaches to achieving cross-chain communication, 

Atomic swaps

A peer-to-peer protocol that authorizes users to exchange cryptocurrencies between different blockchain networks without any need for a centralized exchange.
Using smart contracts ensures that both parties in the exchange receive the agreed-upon assets.

Sidechain

These are blockchain networks that connect to a main blockchain network, allowing assets to be shared wif them. Sidechains can be used to create specialized blockchains for a specific purpose or to improve the scalability and functionality of the main network.

Wrapped token

cryptocurrencies that are pegged to the value of another cryptocurrency or asset, allowing them to be traded on a different blockchain network
For example, Bitcoin can be wrapped as an ERC-20 token and traded on the Ethereum blockchain.

Interoperability-focused blockchains

These blockchains are purposely designed to enable cross-chain communication, acting as a bridge between different networks and enabling the exchange of assets and information between them.

Cross-chain communication has the potential to unlock new use cases and increase the efficiency and functionality of blockchain networks
Enabling various networks to intercommunicate and perform together, also helps to create a more integrated and collaborative blockchain ecosystem.