What is the primary function of the PATCH method in API requests?

The PATCH method in API requests is specifically designed to apply partial modifications to an existing resource. This means that when you want to update a record, the PATCH method allows you to send only the data that you want to change, rather than requiring you to send the entire record. This is particularly useful for optimizing bandwidth and processing time.

For example, if a user's profile needs to be updated to change the email address only, instead of sending the complete profile data using methods like PUT, the PATCH method allows only the email field to be included in the request. This makes updates more efficient and resource-friendly.

In RESTful API design, the ability to modify resources with precision using the PATCH method aligns with best practices for managing state in web services, ensuring that systems are responsive and efficient in handling data updates.