Here is a brief description of what SPDY is ?
SPDY is an Experimental Application layer protocol which augments HTTP protocol with new features and best practices. HTTP and TCP are the standard protocols used for the web today. There is not much we can optimize at the transport level (TCP) so the HTTP protocol at the application layer was rethought. HTTP protocol at the application layer has a lot of drawbacks. Thus SPDY was designed to overcome these drawbacks of HTTP and help load the web Pages faster.
SPDY introduces some of features such as Multiplexing of Streams, Request Prioritization, Server initiated streams and HTTP Header Compression. It has been experimentally determined that page loads are 50% faster in SPDY than in HTTP. There are both client and server level support for SPDY protocol. SPDY is easier to deploy and is also server efficient. SPDY with SSL is also implemented for secure transmission of data over SPDY protocol.
Important goals of SPDY include faster page loads and improved web security. SPDY also supports Bidirectional streams. Most of the client end Browsers such as Firefox, Silk and Chrome now fully support SPDY protocol. At the server side, Servers such as Apache, Jetty etc. are now supporting SPDY. Most of Google Web sites now have completely implemented SPDY protocol.