What are some cool offerings HTTP2 has to offer and what are the challenges?
Is a good explanation of why and what it is.
https://www.cloudflare.com/http2/what-is-http2/
Goes more into performance.
The best features are probably the Multiplexing and Stream Priority.
Jonathan
Breaking things by touching
Cliff Rowley
Thinker, Tinkererer, Dork.
The section "What are the key differences to HTTP/1.x" in this link @mgiambanco posted will tell you everything you need to know to answer your question :-)