HTTP over QUIC - or - HTTP/3

Google has been working on an experimental network protocol named QUIC: "Quick UDP Internet Connections." QUIC abandons TCP, instead using its sibling protocol UDP (User Datagram Protocol). UDP is the "opposite" of TCP; it's unreliable (data that is sent from one end may never be received by the other end, and the other end has no way of knowing that something has gone missing), and it is unordered (data sent later can overtake data sent earlier, arriving jumbled up). UDP is, however, very simple, and new protocols are often built on top of UDP.

QUIC reinstates the reliability and ordering that TCP has but without introducing the same number of round trips and latency. For example, if a client is reconnecting to a server, the client can send important encryption data with the very first packet, enabling the server to resurrect the old connection, using the same encryption as previously negotiated, without requiring any additional round trips.