WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as RFC 6455 in 2011, and the WebSocket API in Web IDL is being standardized by the W3C. WebSocket is distinct from HTTP.A WebSocket is a persistent connection between a client and server. WebSockets provide a bidirectional, full-duplex communications channel that operates over HTTP through a single TCP/IP socket connection. At its core, the WebSocket protocol facilitates message passing between a client and server.WebSocket is a protocol providing full-duplex communication channels over a single TCP connection. Where as, HTTP providing half-duplex communication. Means, server can push information to the client (which does not allow direct HTTP).Socket.IO was created in 2010. It was developed to use open connections to facilitate realtime communication, still a relatively new phenomenon at the time. Socket.IO allows bi-directional communication between client and server.Socket.io is an open-source library created by Guillermo Rauch. It is built with Engine.IO, which is a lower-level abstraction on top of WebSocket technology. The WebSocket API protocol was standardized in 2011.Usually, you would NOT want N socket.io servers each listening on a different port. ... This makes the server infrastructure transparent to the clients which means you can scale the servers up or down without changing the client behavior at all.