Parachains, represent a disruptive approach to blockchain architecture within the Polkadot layer-1 blockchain ecosystem. Polkadot's parachains run in parallel, connected to and secured by the central Polkadot blockchain, called the Relay Chain.
Polkadot's setup facilitates the exchange of data and assets between Parachains, enabling new use cases and applications. Parachains can extend their reach beyond the Polkadot network by connecting to external blockchains such as Bitcoin and Ethereum through cross-network bridges. A parachain builds on the security features of a relay chain, rather than providing its own security.
Key features of parachains
Polkadot's parachain model emphasises specialisation and flexibility. Unlike traditional one-size-fits-all blockchains, each parachain can be tailored to specific use cases. This could be in gaming, identity management, finance or other applications. There are no strict criteria for parachain design, so each blockchain can have its own unique technical design, tokens and governance processes. This enables the creation of customised public or private networks, corporate or community-driven projects.
A key feature of a parachain is that the computations it performs are inherently independent of the relay chain. Polkadot addresses scalability at the basic layer-1 level by distributing transactions across a network of specialised layer-1 blockchains (parachains). This decentralised approach improves throughput and scalability without relying on layer 2 solutions. By allowing transactions to be processed in parallel, Polkadot's parachains increase the efficiency of the entire Polkadot ecosystem.
Polkadot's cross-chain composability enables the exchange of not only tokens, but also different types of data, such as smart contract calls and off-chain information from oracles. This interoperability breaks down silos within the blockchain space, increasing collaboration and creating innovative services. In addition, parachains have the freedom to adopt different governance models, increasing transparency and accountability.