#explain-card ## Introduction [[Substrate]] is a modular and extensible open-source framework for building custom blockchains, developed by Parity Technologies. It provides the core components necessary to create a blockchain, allowing developers to focus on the unique logic and features of their specific application. You can find more information at the [official Substrate documentation](https://docs.substrate.io/). Substrate significantly lowers the barrier to blockchain development. It enables teams to create highly customized and optimized blockchains—such as [[Parachain|parachains]], parathreads, or solo chains—tailored to specific use cases. As the foundational technology behind [[Polkadot]], Substrate fosters an ecosystem of interoperable blockchains, making it a crucial software development kit (SDK) for creating new Layer-1 blockchains or parachains. ## Core Concepts Substrate's architecture is built around several core concepts that provide its flexibility and power: - **FRAME (Framework for Runtime Aggregation of Modularized Entities):** This is a powerful system for building blockchain runtimes (the state transition logic) by composing modules called "pallets." Pallets are reusable pieces of logic for common blockchain functionalities like [[Staking|staking]], governance, and assets, allowing for modular development. - **Wasm (WebAssembly) Runtime:** A key feature of Substrate is that blockchain runtimes can be compiled to WebAssembly (Wasm). This enables forkless runtime upgrades, meaning the blockchain's core logic can be updated by deploying a new Wasm binary on-chain, without requiring a disruptive [[Hard fork|hard fork]]. - **[[Node]] Template & [[Consensus]] Agnosticism:** Substrate provides a node template as a starting point, which includes networking, consensus, and a basic runtime. While it comes with built-in consensus mechanisms like BABE and GRANDPA (used by Polkadot), Substrate is designed to be consensus-agnostic, allowing developers to integrate other consensus algorithms if needed. - **Customizable Pallets:** Beyond the standard set, developers have the freedom to create custom pallets to implement unique features specific to their blockchain, or they can leverage a growing library of pre-built open-source pallets from the community. ## Use Cases Substrate's versatility makes it suitable for a wide range of applications: - It serves as the core framework for the Polkadot network and its parachains, as well as the Kusama network. - Teams can build **application-specific blockchains** tailored for diverse needs such as [[DeFI|DeFi]], gaming, digital identity, or supply chain management. - It can be used to create **private or consortium chains** for enterprise solutions requiring permissioned access. - The framework facilitates **rapid prototyping**, allowing for quick iteration and development of new blockchain concepts. ## Related Concepts (Optional) - Polkadot - Parachain