What is the difference between HTTP/3 and QUIC?

HTTP/3 and QUIC are closely related and are often used interchangeably. In fact, HTTP/3 is an extension of HTTP/2 based on the QUIC protocol developed by Google.

QUIC is a protocol developed by Google that enables data to be transmitted quickly and securely over the Internet. It is built on top of UDP instead of TCP and integrates SSL/TLS encryption directly into the protocol, resulting in faster transfer of data.

HTTP/3 uses the QUIC protocol to make HTTP connections faster and more reliable. Unlike HTTP/1 and HTTP/2, which are based on TCP, HTTP/3 uses the QUIC protocol to allow multiple connections over the same port, thereby improving performance. It is also more resilient to packet loss as QUIC provides the ability to repeat or retransmit packets to ensure they reach their destination.

In summary, QUIC is the protocol that enables the faster and more secure transfer of data, while HTTP/3 is the protocol that is built on top of QUIC and is specially optimized for HTTP connections.