HTTP/1.1 operates sequentially, often leading to head-of-line blocking as it processes one request per TCP connection, necessitating multiple connections for efficient page loading. HTTP/2 was developed to overcome these limitations by introducing a binary framing layer and multiplexing, which enables concurrent requests and responses over a single TCP connection, alongside header compression and server push. Despite these advancements, HTTP/2 can still experience transport-layer head-of-line blocking where a single lost TCP packet can stall all concurrent streams. In contrast, HTTP/3 represents a significant leap by utilizing the QUIC protocol, built upon UDP instead of TCP. QUIC inherently provides stream-level multiplexing, effectively eliminating head-of-line blocking at the transport layer, and offers benefits like faster 0-RTT or 1-RTT connection establishment and seamless connection migration, making it more robust and performant in unstable network conditions. More details: https://abcname.com.ua