One of the most important, basic yet highly used image manipulation method is background removal. It can be necessary to remove background for many reasons. Sometimes there are unexpected background scenes, which includes photobombing, other people, sensitive information, unwanted objects, out of focus parts, and something that spoils the beauty of the image. It is in such cases that background removal is necessary.
For example, an e-commerce site will take photos of their numerous products, but even if it is taken in a well-lit studio or not, the background is usually removed. A single coloured or sometimes transparent background is necessary to use that image in multiple places depending on the purpose.