Just some examples of using the Parallax Scrolling
"Parallax Scrolling" is a web design technique in which the background moves at a slower pace than the foreground. This results in a 3D effect as visitors scroll down the site, adding a sense of depth and creating a more immersive browsing experience.
Parallax is based on optical illusion. Since the human eye perceives objects that are close to us as larger than things farther away, we perceive distant objects as if they were moving more slowly.