Hypertext Transfer Protocol (HTTP)

The HTTP client sends a document identifier with or without search words, and the server responds with hypertext or plain text. The protocol runs over TCP, using one connection per document request. The browser acts as a pipeline, so that as the bytes arrive from the server they can be presented to the reader as soon as they arrive.

– Tim Berners-Lee, et al.; World-Wide Web: An Information Infrastructure for High­Energy Physics; January 1992.

The Hypertext Transfer Protocol (HTTP) is used by web servers to communicate web pages to web browsers. HTTP is used when your browser connects to a web server, requests a web page from the server, and downloads the page. It is the common standard that enables any browser to connect to any server, anywhere in the world.

HTTP was originally designed by Tim Berners-Lee to support the special demands of web communications, with an emphasis on efficiency, and a target page load time of under a tenth of a second. Modern Internet networks can support this type of response provided the page isn’t too large and the server too far away.

Your browser can open more than one HTTP connection at once to download different parts of a web page, downloading the text, graphics, and other objects on the page in different orders. That is why you may see the status messages in the bottom of your browser window switch between a message like “downloading 62% of 15K” to “downloading 38% of 47K” on the same page — there are different HTTP connections.

Some browsers enable you to specify the download priorities so that, for example, graphics are not loaded, text is loaded before graphics, everything is loaded at once, etc. Check your individual browser preferences.

Resources. The following resources provide more information about HTTP: