Web Communication Protocols Overview

HTTP/0.9 was a very simple, one-line protocol used in 1991. It is no longer in use.

HTTP/1.0 introduced a mandatory version number and extensible headers, allowing more information to be exchanged between the client and server.

HTTP/1.1 added support for persistent connections, which means that a single connection can be used for multiple requests and responses, leading to greater efficiency.

A 'keep-alive' header in HTTP/1.0 specifically indicates to the server that the connection should remain open after a request. This was optional and required explicit declaration. On the other hand, in HTTP/1.1, connections are persistent by default, unless specified otherwise by the 'Connection: close' header. This allows for greater efficiency and responsiveness.

The keep-alive header in HTTP/1.0 allows clients to indicate their desire to keep the connection open after a request, improving efficiency by allowing for multiple requests on the same connection. This is in contrast to HTTP/1.1, which defaults to persistent connections making a connection open until explicitly closed.

A protocol that uses UDP instead of TCP, eliminating head-of-line blocking and enabling faster connection setup.

A transport layer protocol built on UDP, designed for fast and reliable communication over the internet. Provides features like connection multiplexing, flow control, and built-in TLS 1.3 encryption.

A problem that occurs in TCP where a single slow packet can block the entire connection, even if other packets are ready to be sent.

A communication pattern where a client repeatedly asks the server for updates. It's often inefficient, as the server continuously answers requests, even if nothing has changed.

A technique that improves upon polling by allowing the server to keep a connection open until there's an update, minimizing unnecessary requests.

A bidirectional communication protocol that allows real-time communication between client and server. Allows for continuous data exchange without requiring repeated requests from the client.

Multiple requests can be sent and received on a single TCP connection. This eliminates the overhead of opening multiple connections and improves efficiency.

The server can proactively send resources the client might need, even before the client explicitly requests them.

HTTP/2 uses frames to transmit data, each frame belonging to a specific stream. Frames are prioritized and controlled to optimize data flow.

HTTP/1.1 allowed only one request at a time on a connection. HTTP/2 improved this by allowing multiple requests to be sent one after another without waiting for the previous response.

HTTP/2's primary advantage is its ability to improve page load times and overall web performance. It achieves this through features like multiplexing, server push, and header compression.

A protocol developed by Google that used HTTP/2-like features to improve web performance before HTTP/2 was adopted.

A server-side technology that enables real-time bidirectional communication between a client and a server over a WebSocket connection.

A technology that allows web servers to push data to client browsers in real-time without the client having to constantly poll for updates.

An HTTP callback mechanism where a server sends a notification to a specified URL when a specific event occurs.

A JavaScript API that enables real-time peer-to-peer communication between web browsers.

A combination of technologies and techniques that enable real-time communication between a client and a server. It often involves long polling, where the client repeatedly checks for updates from the server.

WebRTC is a communication protocol that enables real-time communication between web browsers, using peer-to-peer connections over UDP.

WebRTC uses ICE (Interactive Connectivity Establishment) to establish sessions. ICE employs two key techniques: STUN (Session Traversal Utilities for NAT) and TURN (Traversal Using Relays around NAT).

STUN helps browsers find each other and communicate, by sending special messages to the network to discover their public IP addresses.

TURN acts as a relay server for browsers when they cannot connect directly, allowing them to exchange data indirectly.

WebRTC allows browsers to communicate directly without a server. It's a peer-to-peer protocol.

WebRTC uses two channels: Data Channel for exchanging data like text or files and Media Channel for transmission of audio and video.

WebRTC can be used in many applications like video conferences, live chat, collaborative tools, and real-time gaming.

WebRTC is becoming increasingly popular as it offers real-time communication capabilities without requiring complex server infrastructure.

A technique for streaming data from the server to the client using a hidden iframe. The server continually sends data to the iframe, which triggers events on the client side. This technique is considered a workaround or a hack because it relies on hidden elements.

A technique for retrieving updates from the server using a hidden iframe. It's similar to long polling but leverages the iframe's event handling capabilities to trigger events on the client side. However, it is considered a less efficient and reliable approach compared to WebSocket or Server-Sent Events.

A method to enable long-polling communication using JavaScript's XMLHttpRequest (XHR) object. It keeps an open connection and waits for the server to respond with updates. This is a client-side technique that requires server support for long-polling.

A client-side technique for retrieving data from a server using a JavaScript function call. The server responds with a JSON object as a callback parameter to the function. This technique is often used for cross-domain communication as it does not require a browser extension like XHR for long polling.