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# Schema components

Specify the constituent parts of your schema, including entities, attributes,
and relationships.

## Topics

### Entities

[`class Entity`](/documentation/SwiftData/Schema/Entity)

An object that provides a blueprint for the associated model class.

### Attributes

[`class Attribute`](/documentation/SwiftData/Schema/Attribute)

An object that describes the configuration and behavior of a specific property of a model class.

[`class CompositeAttribute`](/documentation/SwiftData/Schema/CompositeAttribute)

An object that describes an attribute that derives its value by composing other attributes.

### Relationships

[`class Relationship`](/documentation/SwiftData/Schema/Relationship)

An object that describes the configuration and behavior of a relationship between two model classes.

### Internal

[Internal symbols](/documentation/SwiftData/SchemaComponentsInternal)

Restricted-use symbols that the framework requires for macro expansion and
other internal tasks.


---

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