How does a server verify the correctness of the data structure transmitted to it?

The server checks the correctness of the transmitted data structure using validation, which may include:

• Data schemas (JSON Schema, XML Schema): the server compares the received data with a predefined schema to ensure that all required fields are present and have the correct type.
• Business logic level validation: checking the validity of field values (e.g., number ranges, date formats).
• Use of libraries and frameworks: many server platforms provide tools for automatic structure and data type validation.

Example: if the server expects a JSON with fields "name" (string) and "age" (number), it will verify that these fields exist and match the types before processing the request.