Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!
TCP/IP and UDP/IP are low-level data transfer protocols.
HTTP, FTP, SMTP, WebSocket are high-level data transfer protocols.
WebSocket persists a connection and use it for bidirectional data transfering. It is good for real-time applications, e.g., chat and game applications.
WebTransport is a better alternative to WebSocket.
MQTT is a standards-based messaging protocol used for machine-to-machine communication. Smart sensors, wearables, and other Internet of Things (IoT) devices typically have to transmit and receive data over a resource-constrained network with limited bandwidth.