substrate

Substrate is a general term used across sciences and engineering to denote the underlying material, surface, or layer that supports or interacts with other substances or processes. In many contexts, it serves as the base on which reactions, growth, or construction take place.

In biology, a substrate is the substance acted upon by a cell, enzyme, or other biological catalyst. In enzymology, the substrate binds to the enzyme's active site to form an enzyme-substrate complex, leading to a chemical transformation and product release. Substrate specificity describes how enzymes recognize particular substrates.

In materials science and electronics, the substrate is the base material on which films, coatings, or devices are built. Common substrates include silicon wafers for semiconductors and glass or sapphire for optical coatings. The choice depends on thermal, chemical, and mechanical properties.

In geology and soil science, the substrate refers to the underlying rock, soil, or substrate layer beneath a surface or over which a process occurs. It provides structural support and influences weathering and hydrological interactions.

In computer science, Substrate is an open-source blockchain framework by Parity Technologies that enables building custom blockchains and multi-network ecosystems. It provides modular components for consensus, runtime, and governance and underpins the Polkadot network.