What is TCP?
Transmission Control Protocol (TCP) is the long‑standing transport protocol that provides reliable, ordered delivery of bytes between endpoints. It ensures integrity and ordering but can introduce latency due to separate connection and TLS handshakes and head‑of‑line blocking in some scenarios.
What is QUIC?
QUIC (Quick UDP Internet Connections) is a newer transport protocol built on UDP that integrates encryption and reduces connection setup latency. It provides multiplexed streams without the same head‑of‑line blocking issues and supports connection migration for mobile clients.
Why it matters
QUIC aims to reduce page load latency, improve resilience for mobile users, and provide stronger privacy by default. Research and deployments show QUIC can match or improve on TCP's efficiency while adding features that benefit modern web applications.