# Schema

> A formal definition of the structure, types, and constraints of data.

Record: `lexicon:schema`
Kind: artifact
Layer: [Structural Core](https://banes-lab.com/records/layer/structural-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-schema

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Boilerplate](https://banes-lab.com/records/lexicon/boilerplate.md) and before [Compatibility](https://banes-lab.com/records/lexicon/compatibility.md).

## Category

- [Core Vocabulary](https://banes-lab.com/records/lexicon-category/core-vocabulary.md)

## Required by

- [API Contract](https://banes-lab.com/records/architecture/api-contract.md)
- [Data Contract](https://banes-lab.com/records/architecture/data-contract.md)
- [Self-Describing Structures](https://banes-lab.com/records/architecture/self-describing-structures.md)
- [Input Validation](https://banes-lab.com/records/architecture/input-validation.md)

## Linked from

- [Contracts / Interfaces / Compatibility](https://banes-lab.com/ontology/principles/architecture-category-contracts-interfaces-compatibility.md)
- [Metadata / Self-Description / Declarative Systems](https://banes-lab.com/ontology/principles/architecture-category-metadata-self-description-declarative-systems.md)
- [Security / Privacy / Compliance / Governance](https://banes-lab.com/ontology/principles/architecture-category-security-privacy-compliance-governance.md)
- [Infrastructure Concerns](https://banes-lab.com/ontology/lexicon/lexicon-category-infrastructure-concerns.md)