What is QUIC?
Simple. QUIC stands for Quick UDP Internet Connection.
QUIC has taken all the best qualities of TCP connections and TLS encryption and implemented it on UDP.
- Reduced connection times. To establish TLS encryption, the client and the server need to perform a TLS handshake and exchange encryption keys. QUIC replaces this with a single handshake.
- Better performance when data packets are lost. The QUIC protocol allows streams of data to reach their destination independently. They no longer need to wait for the missing data packet to be repaired.
- Stable connections when networks are changed. If you are connected to a web server via TCP and your network suddenly changes, QUIC allows for a smoother transition by giving each connection to a web server a unique identifier. These can be reestablished by simply sending a packet rather than establishing a new connection, even if your IP changes.
- Easier to improve and develop. QUIC can be implemented on the application level, making it a more flexible protocol.
But you'll never see any of this. All you'll see is faster.
So who uses QUIC?
Google Chrome when it connects to Google servers. This includes all of Google's services, i.e. YouTube, Blogger, Hangouts, etc.