Now You See Me: How To Defer, Lazy-Load And Act With IntersectionObserver
▻https://www.smashingmagazine.com/2018/01/deferring-lazy-loading-intersection-observer-api
“In this article, we are going to go out of the scroll darkness and talk about the modern way of lazy-loading resources. Not just lazy-loading images, but loading any asset for that matter. More so, the technique we are going to talk about today is capable of much more than just lazy-loading assets: We will be able to provide any type of deferred functionality based on the elements’ visibility to users.”