The "204 No Content" status code is part of the HTTP response codes used in web communication. It indicates that the server successfully processed the request, but there is no content to send back in the response. This is often used in situations where a client sends a request that does not require any data to be returned, such as a successful form submission. When a client receives a "204 No Content" response, it understands that the request was successful, but there is nothing to display or process further. This status code helps improve efficiency by reducing unnecessary data transfer, making it useful in applications like REST APIs and web services.