When employing an upload field, the system efficiently stores the uploaded file within the Media Library while simultaneously recording its corresponding attachment ID in the database. This unique “number” represents the attachment ID, enabling seamless utilization and display.
With the attachment ID at your disposal, a multitude of possibilities arise. For instance, you can effortlessly create a link using the following format: http://wp.example.net/?attachment_id=n, where ‘n’ denotes the specific attachment ID number.
For further reference on how to retrieve attachment links, you can explore the WordPress codex link provided: https://codex.wordpress.org/Function_Reference/get_attachment_link
By leveraging attachment IDs, you can seamlessly manage and showcase your uploaded files, offering a streamlined user experience.