A Broad Outline of HTTP⁄ 2

Connections are now parallel and fully multiplexed, so multiple data assets can be transferred faster and more efficiently over the same TCP request.

The protocol is binary, so the commands in the form of 0s and 1s that are transferred over the wire are more efficient, unlike the human-readable commands used up to HTTP 1.1.

The new 'server push' concept allows the server to send resources in anticipation of the needs of the client, while still allowing the client to reject the pushed data.

Compressed HTTP headers that avoid the need to re-send headers.

It supports all browsers, so if your site uses HTTP/2, there's no scenario where it prevents a visitor from accessing your site. Newer browsers that are compatible with HTTP/2 will work of course, but those aren't compatible will switch to HTTP 1.1 without so much as a hiccup. Of course, the new protocol doesn't affect how the site looks, just how well it performs or how quickly it loads.

It will directly work with your existing TLS certificate, and you don't need to tweak anything. However, do remember that only secured domains work with HTTP/2 right now, though this should change as more and more browsers add HTTP/2 cleartext support.

You can use HTTP/2 with major existing services like Cloudflare that support all the way up to even HTTP/3

Most hosting services enable HTTP/2 by default. The HTTP/2 web server from Verpex, for instance, works from the get go.