One of the number one protocols that we make use of every single day without ever realising it is that of the hypertext transfer protocol or HTTP. This is the communications protocol used on the World Wide Web for retrieving documents which are interlocked with each other. It is this exact protocol which Tim Berners-Lee used to establish the internet as we know it today. The development of HTTP is a coordinated effort between the World Wide Web Consortium which was founded by Lee and the Internet Engineering Task Force.
It is the standard means of requesting and responding between clients and the web server. Through a web browser, the client makes an HTTP request to the server and as a result it gets one back in the form of the code, style sheets and any necessary files needed to build the page in the browser. The most important means of making these connections is through the use of TCP/IP, however this is not the only means. Furthermore the connections can be direct, or intermediate. Intermediate connections refer to connections made via iFrames, PHP includes, proxies, gateways, tunnels or anything else that can act as a go-between from the client to the server.
In order to make the connection between a client and server, a port has to be used so as a result uniformity had to be created in order to allow these connections without interference. As a result, the standardised port 80 is used for any and all HTTP connections. In the case of the server, the server is always listening on port 80 unless it has been instructed to otherwise. When it receives a request it responds with its HTTP version number, and a status of 200 along with a message such as the webpage itself.
In order to access the resources of a server through HTTP, a Uniform Resource Identifier or URL has to be used. One cannot simply type in the IP address of the server in order to load the requested page as there may be hundreds or even thousands of websites stored on a single server. Making use of the URL allows the client when connecting to the server to inform the server of which section of resources is being requested.
While the internet was officially launched in 1992 by Berners-Lee, the first version of the hypertext transfer protocol was released in 1991. This first version, or HTTP/0.9 was only capable of a single command and that was GET. There was no allowance for POST so there was no dynamics of a website. Furthermore, the only information a client was able to pass to the server was the URL address and nothing more.
By 1996 HTTP/1.0 was introduced and today is still one of the most commonly used protocols today. Most notably is that of proxy servers which regularly make use of this version of the hypertext transfer protocol. While the 1.0 version is still common today, there were needs for changes and as a result, by 1997 HTTP/1.1 was released. This particular version allowed for a whole slew of new commands and features and assisted with making the connections and transfer of resources easier as well as faster.
In 1995 another attempt to upgrade the HTTP was made under the name of PEP or the Protocol Extension Protocol. This was basically an extension to HTTP which would have become version 1.2 had it been approved and succeeded past the experimental stages. A number of working drafts had been developed and information passed around under this experiment. So much in fact that it had even been registered as RFC 2774, but unfortunately it was not to last and every attempt to reference HTTP/1.2 was removed. In February of 2000 a full paper was drafted and released to the public concerning this experimental version of HTTP, but nothing else has come of it. Original Authors: Nick
Edit Update Authors: M.A.Harris
Updated On: 22/12/2008