Polkadot Parachain

Polkadot is a "network of networks", a multi-chain framework where developers build application-specific blockchains (parachains) that share security and interoperability. Unlike traditional blockchains where all applications compete for resources on a single chain, Polkadot enables each application to have its own dedicated blockchain with custom logic, tokens, and governance. Key concepts: Relay Chain (security layer), Parachains (application chains), Substrate (framework for building parachains), and XCM (cross-chain messaging). Developers use Substrate and Rust to build custom blockchains that inherit security from Polkadot's validators.