What specific problem does GraphQL solve by allowing a client to ask for only the data fields it needs from a resource?

The specific problem GraphQL solves by allowing a client to ask for only the data fields it needs from a resource is over-fetching. Over-fetching occurs when a client, which is an application like a mobile app or web browser, requests data from an API and receives more data fields than it actually requires for its current task. A resource is an entity on the server, such as a 'Product' or 'User', which has various data fields (e.g., a 'User' resource might have `id`, `name`, `email`, `ad....