# Introduction to Schema

Schema, a fundamental concept in [OpenAPI Specification(OAS)](https://swagger.io/specification/), is also commonly referred to as a Data Model. A Schema defines the expected data types and properties of API request and response objects.

[JSON Schema](https://json-schema.org/) serves as the standard adopted by Apidog for modeling the data structures employed by your API.

With schemas, you can:

- Define standard data structures (such as an Order object).
- Integrate schemas with automatically generated examples.
- Leverage data structures repeatedly throughout your API projects. 


## Purpose of schema in Apidog

Within Apidog, schemas play a pivotal role in:

- **Designing APIs**: By defining schemas early in the design phase, developers can visualize and refine the data structures that their APIs will handle.

- **Mocking Services**: Apidog utilizes defined schemas to generate mock responses, allowing developers to simulate API behavior and front-end interaction even before the actual implementation.

- **Documentation**: Accurate and comprehensive API documentation is automatically generated based on the schemas, facilitating clear communication with API consumers about the expected data formats and structures.

- **Debugging**: Schemas are used to validate the responses in API debugging, ensuring that the API responses adhere to the defined data models.

## [Create a schema](doc-891343)

Consider the scope of your schema: Will the data be utilized across multiple API sections or APIs, or is it specific to a single use case?

If the data structure is intended for multiple uses, creating a schema facilitates centralized management and consistency.

You can [add a schema](doc-891343) under the "Schemas" directory.

## [Build the schema](doc-891344)

Leverage the user-friendly Schema Editor in Apidog to effectively [build schemas](doc-891344) that align with the JSON Schema specifications.

<p style="text-align: center">
    <img src="https://api.apidog.com/api/v1/projects/544525/resources/340995/image-preview" style="width: 640px" />
</p>

You can also build schemas by [importing from database tables or JSON/JSON schema data](doc-891345).

## Apply the schema
Upon establishing a reusable schema, navigate to the endpoints to reference the schemas in request or response bodies, or in other schemas. By referencing a shared data model, you can maintain consistency and streamline the integration of the data model across various components of your API design.