Substrate
Substrate is an open-source blockchain development framework created by Parity Technologies for building custom, interoperable blockchains. It provides modular components, such as consensus mechanisms, networking, and runtime logic, allowing developers to focus on application-specific logic rather than low-level blockchain infrastructure. It is the foundational technology behind the Polkadot network and enables the creation of parachains that can connect to Polkadot for shared security and cross-chain communication.
Developers should learn Substrate when building custom blockchains that require high flexibility, interoperability, or integration with the Polkadot ecosystem, such as for decentralized applications (dApps), enterprise solutions, or specialized networks. It is particularly useful for projects needing to leverage Polkadot's shared security and cross-chain capabilities, as it simplifies blockchain development with pre-built modules and a Rust-based runtime environment.