Introduction to HTTP/2

Web developers are told that hacks like resource inlining, domain sharding, and image spriting are best practices for improving website performance. But these hacks are just to work around the limitations of an aging protocol. Although HTTP/1.1 has served the world fairly well for the past 15 years, changes to the way in which we use the Internet have pushed this protocol beyond what it was designed to do. The HTTP/2 specification addresses many of these limitations, while also making better use of network resources. Topics to be discussed are HPACK header compression, multiplexing, server push, and security considerations. Basic knowledge of TCP and HTTP/1.1 is recommended.
Beginner : http http/2 protocol specification