HTTP/2
https://www.oreilly.com/learning/http2-a-new-excerpt?cmp=tw-webops-free-info-promo_ilyagrigorik_article

HTTP/2 vs HTTP/1
https://www.thewebmaster.com/hosting/2015/dec/14/what-is-http2-and-how-does-it-compare-to-http1-1/