# CCIP Architecture
Source: https://docs.chain.link/ccip/concepts/architecture
Last Updated: 2025-06-09

> For the complete documentation index, see [llms.txt](/llms.txt).

This section explains the core architecture of the Cross-Chain Interoperability Protocol (CCIP). Learn about the fundamental components and how they interact to enable secure cross-chain communication.

- **[Overview](/ccip/concepts/architecture/overview)**: Get a high-level summary of the CCIP architecture.
- **[Key Concepts](/ccip/concepts/architecture/key-concepts)**: Understand the essential terms and components within the CCIP ecosystem.
- **[Onchain Components](/ccip/concepts/architecture/onchain)**: Explore the on‑chain components, including EVM smart contracts and Solana programs, and Aptos modules, that operate directly on blockchains.
- **[Offchain Components](/ccip/concepts/architecture/offchain/overview)**: Discover the offchain systems that support CCIP operations.