software component

A discrete, self-contained unit of executable code — such as a library, module, middleware, or framework — that provides a defined function or set of functions within a larger system. It is distinguished from the system as a whole by its bounded scope, its independently addressable identity (origin, version, license, known vulnerabilities), and its composability with other such units. In security, compliance, and supply-chain risk management, the field uses the expression to identify the tractable units that must be inventoried (e.g., in a Software Bill of Materials), assessed for provenance and vulnerability, and governed across the software development lifecycle.