Performance optimization in an HTTP/2 world • Yoast

A revolution is currently going on in the underpinnings of the web. HTTP, the protocol your browser uses to connect to your site, has a new version: HTTP/2. This is not something that should concern the average user, but for web developers, it changes how we do performance optimization entirely. In this short article, I want to explain what performance optimization best practices you can do away with, and why. What changed?
The most important thing you should know about the new HTTP/2 is that it no longer requires a new request for each file. This is the modification that makes our performance optimization guidelines change so drastically. In the HTTP1 / HTTP/1.1 world, it’d be faster to combine JS & CSS files and even images, so there would be fewer requests between browser and server. In the HTTP/2 world, this type of optimization is no longer needed and can even become counterproductive.
Can I use this already?
The answer is, fairly simply: yes. If your site is running on HTTPS, then all major current browsers support HTTP/2. You or your hosting company might have to change your server configuration to make sure it supports HTTP/2, but that’s it. Some older browsers
Source: https://managewp.org/articles/14073/performance-optimization-in-an-http-2-world-yoast

source https://williechiu40.wordpress.com/2016/12/23/performance-optimization-in-an-http2-world-%e2%80%a2-yoast/