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Surely, in the address bar of your browser, you have noticed the abbreviation with which all domain names begin - http ( or https ). It means that your browser uses the HTTP protocol to load a web page. Let's figure out why everything is arranged this way in the modern Internet and what is the purpose of this protocol.
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What is HTTP
The abbreviation HTTP itself stands for Hyper Text Transfer Protocol. The HTTP protocol is used to transfer data between a user application (usually a browser) and a web server.
Brief history of the protocol
The creator of HTTP is considered to be Tim Berners-Lee, the "father" of the World Wide Web. Then wordpress web design agency in 1991, the Internet, one can say, practically did not exist. It was developed by Berners-Lee not for some global goals, but to solve a specific problem - to provide access to the information resources of the CERN laboratory.
However, HTTP turned out to be so convenient that already in 1993 the HTTP/0.9 specification was published, which was available to anyone. It contained definitions of key concepts, syntax, but at the same time provided the opportunity to expand and develop the protocol. In addition, the source code of the program was made public, which allowed viewing hypertext transmitted via HTTP. This was literally a breakthrough, marking a new milestone for the World Wide Web.
At first, HTTP was used only for transmitting hypertext directly, but later it became obvious that the protocol was also suitable for binary data - so it began to be used to transmit images and audio files.
Three years after the publication of the first specification, in 1996, the release of HTTP/1.0 saw the light of day. The new version significantly expanded the capabilities of the first specification and introduced a new data type for transmission, application/octet-stream, which officially legalized the transmission of non-text information.
But HTTP/1.1, published in 1999, can rightfully be considered a long-liver among specifications - it has not changed for 16 years. And, by the way, it became the foundation for other protocols.
Not long ago, in 2015, a "draft" version of HTTP/2 appeared. It differs significantly from all previous specifications. In particular, HTTP/2:
is no longer a reworking of the first version of HTTP/0.9;
has a binary data representation format;
It requires encryption and other things.
Who is involved in HTTP data transfer?
From its name alone, you can guess that the HTTP protocol uses text to transfer data, despite the fact that messages sent from the server to the client can contain video, audio, and images.
Who are these client and server?
The client is the one who sends the request.
The server is the one who responds to this request.
Any client request is sent to the server, which processes it and responds, providing data on the client's request. However, their communication is not direct - on the way from the client to the server and vice versa, there are other objects, or more precisely proxy servers.
So, there are three main players involved in data transfer via HTTP: client, web server, proxy server. Let's get to know them in more detail.
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發表於 13:34:57