SPDY (pronounced "SPeeDY"), now HTTP/2, is a networking protocol whose goal is to speed up delivery of web pages
SPDY (pronounced "SPeeDY") is a networking protocol whose goal is to speed up the web. SPDY augments HTTP with several speed-related features that can dramatically reduce page load time:
SPDY allows client and server to compress request and response headers, which cuts down on bandwidth usage when the similar headers (e.g. cookies) are sent over and over for multiple requests. SPDY allows multiple, simultaneously multiplexed requests over a single connection, saving on round trips between client and server, and preventing low-priority resources from blocking higher-priority requests. SPDY allows the server to actively push resources to the client that it knows the client will need (e.g. JavaScript and CSS files) without waiting for the client to request them, allowing the server to make efficient use of unutilized bandwidth.
With the approval of HTTP/2, SPDY has now been officially adopted by the IETF and is now a web standard. As a result, Google (the initiators of SPDY) have given mod_spdy to the Apache Foundation. apache-2.2 will still need mod_spdy, but Apache 2.4.7 and later have(or will soon have) it included natively. nginx also includes mod_spdy natively.
