Artwork can have many different layers in it. All these layers are placed over one background. The background of any artwork can be kept plain or can be adorned with images, icons or any other solid colors.
When such images, icons or solid colors are used as the base of the artwork, they have termed background images. Many e-commerce platforms have their own set of background image protocols that are used to create a uniform and distinct effect on their feed.
For instance, Amazon emphasizes their vendors put a white or plain background for the products that they are uploading to their Amazon store.