JSON Schema extensions refer to custom extensions made to the standard JSON Schema to meet specific requirements or provide additional functionality. JSON Schema is a standard for validating JSON data structures. However, in some cases, the standard JSON Schema capabilities may not be sufficient to describe complex validation logic or other special requirements. Through extensions, developers can add custom properties, rules, or descriptions to achieve more flexible JSON data validation.Apidog JSON Schema extensions refer to the custom extensions provided by Apidog to enhance standard JSON Schema functionality and meet specific requirements for API development and testing.