HTTP stands for HyperText Transfer Protocol, Hypertext Transfer Protocol.
Hypertext
The so-called "text" (Text), it means that HTTP transport is not TCP / UDP protocols underlying these chaotic in tokenized binary packages (datagram), but a full, meaningful data can be browser, server, so the upper layer application processing.
In the early Internet, "text" is just a simple text characters, but to the present, meaning "text" has been greatly expanded, images, audio, video, and even compressed, can be counted in the eyes of HTTP "text".
The so-called "hypertext" is "beyond the text normal text", which is a mixture of text, images, audio, and video, the most critical is contain "hyperlinks", able to jump from a "hypertext" to the other a "hypertext" to form a complex nonlinear relationship between structure, mesh.
For the "hypertext," we are most familiar with it should be HTML, and it itself is just plain text files, but the interior is defined links to pictures, audio, video, etc. with a lot of labels, and then through the interpretation of the browser, presented us front page that contains a variety of audio-visual information.
transmission
Computers and the online world, there are countless various roles: CPU, memory, bus, disk, operating system, browser, gateways, servers communicate with each other ...... between these roles is also bound to have a variety, a wide variety of protocols , use is also different, such as broadcast protocol, addressing protocol, routing protocol, tunneling protocol, election protocol and so on.
HTTP is a "transfer agreement", the so-called "transfer" (Transfer) is actually very good understanding, a bunch of things is to move from point A point B, or move from point A point B, that is, "A <=== > B ".
Do not underestimate this simple action, it also contains at least two important information.
The first point, HTTP protocol is a "two-way agreement."
That is, there are two basic participants A and B, from B to A beginning end, between the A and B data instead of two-way one-way flow. We usually initiates transmission operation to the requesting party, called A, B transmitted to the rear is called responder or responder. We take the most common Internet surfing here as example, the browser is requesting party A, Netease, Sina these sites is the responder B. The two sides agreed to communicate with the HTTP protocol, the browser then sends some data to the site, the site and then send some data back to the browser, the last show on the screen, you can see all kinds of interesting news, videos.
Second, although the data is transmitted between A and B, but no limitation only two characters A and B, allowing the middle "transit" or "relay."
Thus, on the transmission mode from "A <===> B", became "A <=> X <=> Y <=> Z <=> B", the transmission process A to B may be present in any number a "middleman", and these middlemen are also compliant with the HTTP protocol, they do not disturb the basic data transfer, you can add extra features, such as security authentication, data compression, transcoding, etc., optimize the entire transport process.
protocol
HTTP is the essence of a protocol that specifies the communication exchange norms of communication between the two sides.
to sum up
- HTTP is used in the computer world, a protocol that establishes norms exchange of communications between a computer and various associated control and error handling
- HTTP designed to transfer data between two points, can not be used for broadcast, the routing addressing or
- HTTP hypertext transfer of data is text, images, audio, video, etc.
- HTTP is an important foundation technology to build the Internet, it is no entity, dependent on a number of other technologies to achieve, but many also rely on its technology