Sự khác biệt giữa HTTP 2.0 và HTTP 1.1

First of all, HTTP/2 only supports encrypted connections (TLS), even though it is not required according to specs, there are no servers or clients which support unencrypted HTTP/2. The second most significant improvement is multiplexing support: servers can now parallel multiple responses within single connection (check demo at https://http2.akamai.com/demo). And the last major change is support of Server Push feature, which allows to inform client of needed resources before HTML has been loaded.

You can read all specs and FAQ at https://http2.github.io

P. S. Viblo, actually, uses HTTP/2 both for web pages and web sockets.