A protocol is a set of norms and rules that are applied to guide an action or a process. If we focus on the field of computing , the notion is linked to the guidelines that are used to establish a communication process between various computers or systems.
HTTP , meanwhile, is an acronym from the English expression Hypertext Transfer Protocol : that is, Hypertext Transfer Protocol . This is the communication protocol used to transfer information through the World Wide Web .
Before explaining in detail what the HTTP protocol refers to, it is important to remember the structure proposed by the open systems interconnection model, known as the OSI model . This model recognizes eight layers in networks : the lowest is the physical layer , while the highest is the application layer .
The HTTP protocol acts precisely at the application level . Its function is the definition of the semantics and syntax that computer programs use to communicate on the Web (the computer network formed by the interconnection of hypertext documents, which can be accessed through the Internet).
It can be said that the HTTP protocol indicates how browsers ( software ) should communicate with the servers ( computers or computers ) that host the information. What the user does is enter the address of the website in the browser and it, after completing various steps, requests the resources from the server to finally display the data (texts, videos, images, etc.) on the screen.
Speed and security in data transfer are becoming increasingly important, both for Internet service provider companies and for users of all types. In 2015, the HTTP/2 protocol emerged, a new version that promised a significant increase in these aspects, among several other advantages.
It is important to mention that its adoption by the sites was not immediate, despite the fact that among the improvements was a more effective positioning (that is, it makes the sites more visible in the search results). In fact, the semantics do not change with respect to the previous version (the HTTP 1.1 protocol), meaning that its status codes and headers, among other things, remain intact. The main difference is in the way the information is transferred.
Below we will see some of the advantages that the HTTP/2 protocol has over 1.1 in terms of search engine positioning, thanks to which loading times are considerably reduced:
* is a protocol and is binary : the previous version was textual , and this made the processes more complicated because it required translation into binary. Furthermore, transfer errors were more frequent;
* multiplexing : while with the HTTP 1.1 protocol the client had to send a request to the server and wait for the response before being able to send the next one, version 2 multiplexing allows the sending of more than one file simultaneously (the quantity exceeds all six);
* headers are compressed with HPACK : this compression increases speed and efficiency because it eliminates certain fields that have been duplicated;
* server push : the server has the possibility of sending more than one response even if the user has not yet requested them, with the condition that neither the protocol nor the host for the URLs changes;
* ALPN extension : on the initial connection, both client and server can use whatever protocol they want, safely in any case. If the browser does not offer support for HTTP/2, then the resources will be served in the previous version.