Glossary

• API — a set of tools for building software that includes rules for how said software should act.

• Block Headers — the method by with distributed ledgers (blockchains) identify block position, number, or height, and notate where in the chain a block belongs.

• Bridges — a connecting layer that will enable existing blockchains with their own state-histories and methods of consensus to link with polkadot without having to be a native parachain.

• CI — continuous integration, a term for regularly synchronizing developer states to a shared mainline.

• Client Implementation — code is run on the client machine or in-browser.

• Codebase — the complete source code that is used to build an application, protocol, or any particular software.

• Connectivity Management — managing network connections to connect only to relevant parties: e.g. collators or validators

• Contracts Repo — an open-source code repository, located on github, in which Polkadot keeps smart contracts used by the client.

• Devp2p — the backbone of Ethereum, working as a secure networking system or communication layer that allows for peer-to-peer connection and more while remaining simple in nature.

• Full Mode — a complete validation state, akin to a full node on another chain.

• Interpreter — a program that directly executes code without precompiling into another application or machine learning program.

• IPFS[1] — a distributed file system aimed at world-wide connection for use as a database or subsystem like HTTP with the potential to realize a serverless internet.

• Kademlia [2] — a technology used to back file peer-to-peer sharing systems like IPFS and bittorrent using decentralization and denial of service resistance.

• Kovan — a Parity Technologies-built public Ethereum test network.

• Libp2p — a modular, feature rich networking stack (computer networking suite). It backs a technology called IPFS (InterPlanetary File System). This more advanced system seeks to power a distributed web that treats web data a bit like bittorrent handles files.

• Multiplexing — mechanism that will be used to connect devp2p to libp2p.

• Node — a client that stores the entire blockchain and which has the ability to receive and broadcast new blocks and transactions to the network.

• Parachains — Polkadot’s natively supported blockchains that gain consensus using the greater network’s consensus mechanism, and which add to and benefit from pooled security.

• Ping Protocol — times the round-trip for sent and received messages.

• Polkadot JavaScript implementation — an effort to provide a collection of tools, utilities and libraries for interacting with the Polkadot network from JavaScript.

• Polkadot Networking Protocol — a protocol for exchanging blocks, transactions, block candidates, consensus messages, and more over the network.

• Pooled Security — a feature native to Polkadot’s architecture allowing each parachain and the relay chain to utilize the entire network’s set of validators to add additional security and strength to the overall network, and to benefit from the network effect of the total ecosystem.

• Proof of Authority (PoA) [3] — a replacement for Proof-of-Work often used for private blockchains. It does not depend on a distributed set of users and nodes to solve arbitrarily difficult mathematical problems (how Proof-of-Work functions), but instead uses a set of “authorities” — nodes that are explicitly allowed to create new blocks and secure the blockchain.

• Proof of Concept (PoC-1) — an early experimental version of our application that demonstrates feasibility and early functionality.

• Proof-of-Stake — a consensus mechanism wherein participants (stakers) lock token-holdings into a contract that requires them to validate transactions in exchange for block rewards or transaction fees, thereby replacing the function of miners in a Proof-of-Work system by adding distributed security through a staking incentive (interest earned).

• Proof-of-Work — a decentralised consensus mechanism by which participants (miners) are paid to solve blocks and to validate transactions using computing power to solve arbitrarily difficult mathematical equations.

• Pwasm — Parity’s version of a WebAssembly environment which can be used for blockchain execution.

• Refactoring — restructuring existing code without changing its purpose, usually for efficiency, simplicity, or orderliness.

• Relay Chain Contract — One of the contracts deployed on the Relay Chain that govern the behaviour of Polkadot.

• Repo — short for a git code repository.

• RPC layer — “Remote Procedure Call layer”; a client-server layer where software will be coded to run tasks on non-local machines as if they were native/local operations.

• Rust[4] — an open source programming language similar to C++, but intended to provide better memory safety while maintaining performance.

• Solidity — Ethereum’s native coding language.

• Solium Linting — used to check for errors in code in Ethereum’s native coding language.

• Staking Incentives — the foundational motivating factor by which token-holders are incentivized with a high interest rate to lock their token-holdings into a contract that requires them to validate transactions in exchange for block rewards or transaction fees.

• Validator Sets — groups of accounts which are allowed to participate in consensus, and which validate transactions and blocks.

• WebAssembly (wasm) — a quick, web-centric coding language with roots in javascript, ideal for in-browser client-side use, with support for compilation from C and C++, and Rust among other languages.