What does “remove bg” actually do?
“Remove bg” is shorthand for removing the background of an image — keeping the foreground subject and making every other pixel transparent. The result is usually saved as a PNG, because PNG supports an alpha channel that stores transparency. You can then place that cut-out on any colour, gradient or photo without a visible box around it.
Doing this by hand in Photoshop means tracing edges with the pen tool or painting a layer mask, which can take 10–30 minutes for a photo with hair. An AI background remover does the same job in a second by predicting, pixel by pixel, how much of each point belongs to the subject.







