Intro to Polkadot Parachains

Andrei Popescu
Loom Network
Published in
4 min readJun 3, 2021

This is the first part of our series about the Polkadot. First, let’s try to define in a few words what Polkadot is — Polkadot is a blockchain of blockchains and, at the heart of it, sit the concepts of the relay chain and parachains.

If this sounds like mumbo jumbo at the moment, don’t worry. This blog post will explain what the relay chain and parachains are, and how Polkadot aims to solve the interoperability and scalability problems that other blockchains still have to cope with.

The Relay Chain

The relay chain is a blockchain that sits at the center, and all other blockchains connect to it. Now comes the interesting part — the relay chain is only responsible for the network’s security, consensus, and cross-chain interoperability. Let that sink in for a minute before we move on.

In practice, this means that there will be a limited small number of transaction types on the relay chain (governance, auctions, consensus) and smart contracts won’t even be supported. Essentially, as the Polkadot Wiki states, “other specific work is delegated to the parachains, which have different implementations and features.”

And now comes the cool part. Polkadot can also interact with blockchains that use their own finalization process such as Ethereum, Bitcoin, or Tezos through something called bridge parachains. Bridge parachains use a queuing mechanism based on a Merkle tree and validators make sure that transactions are moved from the output queue of the source parachain to the input queue of the destination parachain.

If you’re following along, you may now be wondering who collects parachain transactions. Well, this is what collators do. They run full-nodes for both their parachain and the relay chain in order to aggregate transactions performed on a parachain and produce proofs for each state transition. The proofs are then validated by validators on the relay chain.



Parachains are independent blockchains that are optimized for their own use-cases, and they plug themselves into the relay chain to exchange assets and data. Parachains run in parallel, have their own independent consensus mechanism, use their own tokens but, as we mentioned in the previous section, parachains always rely on the relay chain for security and cross-chain interoperability.

All computations performed on a parachain are independent and the only requirement is that parachains “must be able to generate a proof that can be validated by the validators assigned to the parachain.”

Let’s compare this to how Ethereum works. On Ethereum, computation is performed by smart contracts that are essentially competing for the same computing resources. As you already know, this leads to high costs and congestion.


To sum up, while Ethereum tries to perform computations on a single huge virtual computing machine, Polkadot relies on a multitude of interconnected single-purpose blockchains that perform transactions in parallel and securely exchange data through the relay chain. Thus, Polkadot creates a network of blockchains where any asset on one blockchain can be used by other blockchains, and, as the relay chain is responsible to provide the network’s security, less resources are required to secure each individual parachain.

Putting the Pieces of the Puzzle Together

As you already know, from the very beginning, Loom Network aimed at providing a scaling solution for Etherem dapp developers. As we’ve already mentioned in the previous section, the Polkadot relai chain chain will not support smart-contract and it is envisioned that developers will build their dapps on one of the smart-contract capable parachains. Our mainnet Basechain already provides an EVM-compatible smart-contract platform, so an integration with Polkadot will allow developers to build dapps that can:

  • Utilize tokens that are native to the Polkadot ecosystem.
  • Use the innovative features provided by other Polkadot parachains.
  • Develop, test, and deploy smart-contracts using the extensive tooling available to Ethereum developers.

For example, a developer could build a dapp that’s backed by a set of smart contracts deployed on Basechain, while using the Crust Network parachain for decentralized cloud storage, and the KILT parachain for credential verification.

Also, Basechain’s existing BSC Transfer Gateway — a two-way bridge to Binance Smart Chain, will be upgraded to allow other Polkadot parachains to transfer tokens to BSC and back, and to call smart-contracts deployed on BSC. Furthermore, BSC dapps will be able to access tokens from the Polkadot ecosystem.

This article has barely scratched the surface of what Polkadot is and how it compares to other blockchains. Stay tuned for more on this in our next articles.

Loom Network is building an ecosystem of blockchains for the next generation of DeFi protocols, NFTs, and high-performance multi-chain dapps. At the core of this ecosystem is our Basechain network — already live in production, audited, and battle-tested.

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