A semantic layer is a business-friendly abstraction layer that defines shared concepts, metrics, and definitions on top of raw data. It translates technical data structures into consistent, human and machine understandable meaning, ensuring that both people and AI systems interpret numbers and metrics the same way.

Why it matters:
By establishing agreed definitions and metrics, a semantic layer prevents misinterpretation and disagreement over what data represents. This consistency is essential for AI systems, which rely on clear meaning to reason accurately and deliver trustworthy results at scale.