像幻灯片一样滚动页面

I came across apples new pages for iPhone5C, iPhone5S, Mac Pro and noticed a nice effect that they seem to be doing for their product pages. I stead of just having the user scroll freely throughout the page, they set up slides (for lack of better term) that when the user scrolls, no matter the amount, they only are able to go through the slides one at a time.I came across apples new pages for iPhone5C, iP