Welcome to the Polkadot Wiki! This central source of truth contains guides for interacting with the core functionality. Our wiki has three main sections: Learn (for learners), Build (for people that want to build on Polkadot), and Maintain (for people that want to maintain the network).
What is Polkadot?
Polkadot enables scalability by allowing specialized blockchains to communicate with each other in a secure, trust-free environment.
Polkadot is built to connect and secure unique blockchains, whether they be public, permission-less networks, private consortium chains, or oracles and other Web3 technologies. It enables an internet where independent blockchains can exchange information under common security guarantees.
Polkadot is a living network with the core pillars of governance and upgradability. The network has an advanced suite of governance tools and, using the WebAssembly standard as a "meta-protocol", can autonomously deploy network upgrades. Polkadot adapts to your growing needs without the risks of network forks.
Note: If you haven't heard of Governance before, a great place to start is the Governance page
By connecting these dots, Polkadot serves as a foundational part of a decentralized web, where users control their data and are not limited by trust bounds within the network.
Back in the early 2000's, when the internet was gaining popularity for the first time, the internet featured read-only, static, basic webpages. The online connected world at the time was only the beginning of virtual data, identities, and more. The internet during this time was also called the Web 1.0.
As social media platforms and online businesses began to emerge, the internet transformed into the Web 2.0. This upgraded internet, which we still use today, features dynamic, interactive webpages, where users can read and write information plus publish their own for others to see. However, this version of the web comes with downsides, dealing with data control, privacy issues, and trust. This is where the Web 3.0 comes into the picture.
The Web 3.0 is taking centralized applications and turning them into decentralized, trust-free protocols. The goal is to transform the internet into a decentralized web, where users control their own data and identity in a trust-free environment. The Web 3.0 movement aims to remove intermediaries and build a trustless infrastructure.
To learn more of the Web3 movement, check out this video from the Web3 Summit
How does Polkadot work?
The Polkadot network uses a sharded model where shards - called "parachains", allow transactions to be processed in parallel instead of sequentially. Each parachain in the network has a unique state transition function (STF). Polkadot has a Relay Chain acting as the main chain of the system. Based on Polkadot's design, as long as a chain's logic can compile to Wasm and adheres to the Relay Chain API, then it can connect to the Polkadot network as a parachain.
Parachains construct and propose blocks to validators on the Relay Chain, where the blocks undergo rigorous availability and validity checks before being added to the finalized chain. As the Relay Chain provides the security guarantees, collators - full nodes of these parachains - don't have any security responsibilities, and thus do not require a robust incentive system. This is how the entire network stays up to date with the many transactions that take place.
In order to interact with chains that want to use their own finalization process (e.g. Bitcoin), Polkadot has bridge parachains that offer two-way compatibility, meaning that transactions can be made between different parachains.
The Cross-Chain Messaging Protocol (XCMP) allows parachains to send messages of any type to each other. The shared security and validation logic of the Relay Chain provide the environment for trust-free message passing that opens up true interoperability.
To watch a short, beginner-friendly animation on Polkadot, check out our Polkadot Explainer video
Why should you use Polkadot?
Whether you're a blockchain developer or if you're interested in taking part of Polkadot's community, Polkadot offers a platform for everyone. This wiki offers a place for builders and maintainers to utilize tools and for brand-new learners to dive into educational material.
For brand-new learners of Blockchain technology:
- The Blockchain Fundamentals MOOC course is a great introduction to start familiarizing yourself with blockchain concepts such as cryptography and networks, and how these play into things like decentralization and cryptocurrency.
This is recommended for users with backgrounds of all levels, and the course is free!
For brand-new learners of Polkadot:
Polkadot's original white paper is a technical summary around one possible direction of implementing the Polkadot network. This paper uses rationale and technical details to support why this direction is beneficial. This original white paper also explains how Polkadot's core components work together to build this decentralized network.
Polkadot's overview paper is an updated version of the white paper that describes the protocol in more technical terms. We would recommend reading this overview paper if you are interested in digging more into the protocol itself.
Polkadot's light paper is a visual, easy to read, and less technical introduction into its blockchain technology. This paper dives into the components of Polkadot but is understandable for both a non-technical and technical reader.
Polkadot's specification is a Github repository that holds the latest Polkadot Host protocol specification, Polkadot's specification tests of the many components of the network, and the Polkadot Runtime specification. This repo holds algorithms and explores how various processes function in the Polkadot network. The Polkadot specification takes Polkadot's ideas and concepts from the light and the white paper but focuses on the technical specs of the technology.
To start interacting with Polkadot:
For brand-new learners of Kusama, Polkadot's canary cousin network: To learn more about how to build and maintain on the Kusama network, please head over to our Kusama Guide.
- Polkadot Crowdcast - List of all Crowdcast webinars that the Web3 Foundation has done.
- Polkadot Explorer - Browser for the Polkadot network; can be used for Polkadot, Kusama, or any Substrate-based chain.
- Polkascan - Real-time multi-chain data for Polkadot Relay Chain and Parity Substrate chains.
- Subscan.io - Explorer for Substrate based chains.
- Polkadot Overview - Dr. Gavin Wood presents an overview of Polkadot. (Video)
- Polkadot Overview - Dr. Jutta Steiner presents Polkadot. (Video)
- Polkadot & Substrate Overview - Dr. Gavin Wood presents Substrate (blockchain in-a-box + VM) and Polkadot, and builds a blockchain on-stage in 30 minutes using Substrate. (Video)
- Community / Ecosystem - List of community rooms and channels to talk to others about Polkadot.
- Sample Applications - Sample applications that are built on or currently being built for Polkadot.
- Contributing Guide - Rules for contributing to the wiki.
- Polkadot Knowledge Base - Troubleshooting resources for specific errors and problems.