2.3 Design system vs component library

A component library is one implementation layer of a design system.

A design system additionally includes:

rationale
principles
accessibility requirements
usage guidance
content guidance
tokens
design assets
contribution rules
versioning
governance
release strategy
documentation

Diagram source

Mermaid

flowchart LR
    DS[Design System]
    DS --> T[Design Tokens]
    DS --> CL[Component Library]
    DS --> DL[Design Language]
    DS --> DOC[Documentation]
    DS --> GOV[Governance]
    DS --> UX[UX Patterns]
    DS --> CG[Content Guidelines]
    DS --> QA[Testing & Quality]

You can have a component library without a true design system.

A healthy design system almost always includes one or more component libraries.