The QUIC protocol (Quick UDP Internet Connections) is an entirely new protocol for the web developed on top of UDP instead of TCP. Some are even (jokingly) calling it TCP/2. The really interesting bit about the QUIC protocol is the move to UDP. Now, the web is built on top of TCP for its reliability as a transmission protocol. To start a TCP connection a 3-way handshake is performed. This means additional round-trips (network packets being sent back and forth) for each starting connection which adds significant delays to any new connection.
Full article