What improvements does HTTP/2 offer over HTTP/1.1?

HTTP/2 improvements: Multiplexing (multiple streams over single connection - no head-of-line blocking), Binary framing (efficient parsing), Header compression (HPACK - reduces redundancy), Server push (proactively send resources), Stream prioritization. Single connection per origin reduces TCP overhead. Requires HTTPS in practice. HTTP/3 further improves with QUIC (UDP-based, no TCP head-of-line blocking, faster handshake, connection migration).