Glossary
HTTP/3
HTTP/3 is the latest HTTP version, built on the UDP-based QUIC transport to cut connection setup time and eliminate head-of-line blocking.
HTTP/3 is the newest version of the HTTP protocol. Its defining change is the transport layer: instead of TCP, it runs over QUIC, a protocol built on UDP that bakes encryption and multiplexing into the transport itself.
Why QUIC matters
- Faster handshakes — connection and
ssl-tlssetup are combined, often in a single round trip (or zero on resumption). - No transport-level head-of-line blocking — a lost packet in one stream does not stall the others, unlike
http-2over TCP. - Connection migration — a session survives a network change (e.g. Wi-Fi to mobile) without reconnecting.
Why it matters for hosting
HTTP/3 improves performance on lossy or mobile networks, helping core-web-vitals. Support is rolling out across major CDNs and servers like nginx and litespeed. Because QUIC uses UDP, some restrictive networks block it — clients then gracefully fall back to HTTP/2.
See also
HTTP/2
HTTP/2 is a major revision of HTTP that multiplexes many requests over one connection, reducing latency versus the older HTTP/1.1.
HTTPS
HTTPS is HTTP layered over TLS encryption, so data exchanged between browser and website stays private, authenticated, and tamper-proof.
SSL/TLS
SSL/TLS is the encryption protocol that secures connections between browsers and servers, enabling HTTPS and protecting data in transit.
CDN (Content Delivery Network)
A CDN is a worldwide network of edge servers that cache and serve your site close to visitors, cutting latency and absorbing traffic spikes.