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A scalable, interoperable & secure network protocol for the next web

Any type of data across any type of blockchain

Polkadot is a network protocol that allows arbitrary data — not just tokens — to be transferred across blockchains.

This means Polkadot is a true multi-chain application environment where things like cross-chain registries and cross-chain computation are possible.

Polkadot can transfer this data across public, open, permissionless blockchains as well as private, permissioned blockchains.

This makes it possible to build applications that get permissioned data from a private blockchain and use it on a public blockchain. For instance, a school’s private, permissioned academic records chain could send a proof to a degree-verification smart contract on a public chain.

Network Glossary

Polkadot unites a network of heterogeneous blockchains called parachains and parathreads. These chains connect to and are secured by the Polkadot Relay Chain. They can also connect with external networks via bridges.

Connecting the dots

Relay Chain

The heart of Polkadot, responsible for the network’s shared security, consensus and cross-chain interoperability.


Sovereign blockchains that can have their own tokens and optimize their functionality for specific use cases.


Similar to parachains but with a pay-as-you-go model. More economical for blockchains that don’t need continuous connectivity to the network.


Allow parachains and parathreads to connect and communicate with external networks like Ethereum and Bitcoin.

Consensus Roles


Secure the Relay Chain by selecting trustworthy validators and staking DOT.


Secure the Relay Chain by staking DOT, validating proofs from collators and participating in consensus with other validators.


Maintain shards by collecting shard transactions from users and producing proofs for validator.

Governance Roles

Council Members

Elected to represent passive stakeholders in two primary governance roles: proposing referenda and vetoing dangerous or malicious referenda.

Technical Committee

Composed of teams actively building Polkadot. Can propose emergency referenda, together with the council, for fast-tracked voting and implementation.

Diagram of Polkadot’s relay chain

Built with the best technology

Polkadot’s relay chain is built with Substrate, a blockchain-building framework that is the distillation of Parity Technologies’ learnings building Ethereum, Bitcoin, and enterprise blockchains.

Polkadot’s state machine is compiled to WebAssembly (Wasm), a super performant virtual environment. Wasm is developed by major companies, including Google, Apple, Microsoft, and Mozilla, that have created a large ecosystem of support for the standard.

Polkadot’s networking uses libp2p, a flexible cross-platform network framework for peer-to-peer applications. Positioned to be the standard for future decentralized applications, libp2p handles the peer discovery and communication in the Polkadot ecosystem.

The Polkadot runtime environment is being coded in Rust, C++, and Golang, making Polkadot accessible to a wide range of developers.

Parachains: parallel transaction processing

Parachains are specialized blockchains that connect to Polkadot. They will have characteristics specialized for their use cases and the ability to control their own governance.

Interactions on parachains are processed in parallel, enabling highly scalable systems.

Transactions can be spread out across the chains, allowing many more transactions to be processed in the same period of time.

Current method:
Single transaction

Diagram of a single transaction

Polkadot method:
Multi parallelized transactions

Diagram of multi parallelized transactions
Learn more about parachains

Groundbreaking Technology

Polkadot is solving many of the problems that have held back blockchain technology so far — all in one place, without compromising.

A better security model

In both Proof-of-Work and Proof-of-Stake systems, blockchains compete with each other over resources to secure their networks, and blockchains are easily attacked until they develop a significant community to support their network.

Polkadot takes a different approach by letting blockchains pool their security, which means that the blockchains’ security is aggregated and applied to all.

By connecting to Polkadot, blockchain developers can secure their blockchain from day one.

XCM: a secure cross-chain communication standard

For blockchains to work together and form the basis of Web3, they need a common language for communication. Polkadot sets the standard with XCM, a cross-consensus communication format and programming language that allows blockchains of different designs to securely exchange arbitrary data, code, and value. In this way, a new wave of rich cross-chain applications and services can be built that tap into the features and benefits of different chains.

Learn more about XCM

Next-generation Proof-of Stake

Polkadot pioneers an advanced, highly-efficient form of proof-of-stake called Nominated Proof of Stake (NPoS). NPoS enables greater decentralization and fair representation by evenly distributing stake, allowing all DOT holders to participate in staking, and balancing the interests of smaller and larger DOT holders.

DOT holders can help secure the network and collect DOT rewards by staking as a nominator or a validator. With Polkadot’s native nomination-pools, anyone with as little as 1 DOT can stake and collect rewards.

Learn more about Staking on Polkadot

A green, energy-efficient protocol

It’s hard to get behind blockchain as the next technological revolution when it wastes so much energy. Polkadot is designed to power the web’s next big wave of innovation, without the high energy consumption of conventional proof-of-work blockchains.

Polkadot’s Nominated Proof-of-stake (NPoS) model uses a small fraction of the energy consumed by conventional blockchains, and has the lowest carbon footprint among proof-of-stake protocols analyzed in recent research.

Transparent on-chain governance

Updates to the protocol happen fork-free via transparent on-chain voting, so protocol development never stalls due to the lack of a clear process. The relay chain uses a sophisticated governance mechanism that is designed to establish a transparent, accountable and binding process for resolving disputes and upgrading the network.

DOT tokens are used to participate in governance decisions, including tabling proposals, voting, and bonding.

Parachains are free to design their own governance mechanisms, allowing for maximum freedom without affecting other parachains.

Learn more about Polkadot’s governance

On-chain treasury for decentralized project funding

Polkadot’s governance system also features an on-chain treasury that the community can use to fund projects that benefit the network. Any DOT holder can submit project funding and bounty proposals, and can nominate community members for tips based on work completed.

With tens of millions of DOT available for spending, the treasury represents a powerful resource for fueling Web3 innovation.

Learn more about the Polkadot treasury

GRANDPA: a trustworthy consensus algorithm

Polkadot uses its original GRANDPA (GHOST-based Recursive Ancestor Deriving Prefix Agreement) consensus for a more secure and resilient network.

Under good network conditions, GRANDPA can finalize blocks nearly instantly. Under bad network conditions, like a network partition, GRANDPA can finalize large quantities of blocks (theoretically millions) at once when the partitions resolve.

Learn more about GRANDPA


The launch of Polkadot v1 began in May 2020 with the Relay Chain genesis block and finished in December 2021 with the launch of parachains. Several post-launch developments and optimizations are expected for the coming year and beyond.

See Launch Roadmap

What are teams building on Polkadot? Just a few examples:

Smart contract chains with WebAssembly smart contracts (Astar, Moonbeam)

Data curation networks that connect all file storage chains into curated data sets

Oracle chains that make off-chain data available to all contracts on the Polkadot network (Chainlink)

Identity chains that link accounts to a persistent identity and enable access to other parachains through fewer accounts (Kilt)

Financial chains that allow you to hold all your assets in one portfolio, including via bridges to Bitcoin, Ethereum, Bitcoin Cash, Litecoin and ZCash (Acala)

Internet of Things chains that set IoT standards for machine-to-machine communication (Robonomics)

Zero Knowledge privacy chains, or bridges to existing ZK-snarks chains

File storage chains that incentivize storing data on-chain

Bridge to Ethereum, allowing Ethereum smart contracts to interact with the Polkadot network

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