Today, the Internet will not surprise anyone. Access to this network is carried out daily by a huge number of users. According to 2015, the number of connected users exceeded 3.3 billion. True, not everyone knows what the structure of information resources of the Internet is in technical terms. Most of this, in general, is not necessary. However, the foundations laid down in the principles of the functioning of the World Wide Web, at least at the initial level, still need to know.
What is the Internet in modern interpretation
In general, when it comes to the modern Internet, quite often the concept of the World Wide Web or the Web is used instead, which combines computers from all over the world.
In general, it is true, but here one clarification should be made. As you know, no computer connects directly to the Internet, only through a service provider, to which God is still connected, knows how many other terminals or mobile devices. It turns out that they are all united in one network. And in this sense, the Internet is called a "network of networks."
Indeed, the structure of the Internet is based on a combination of, so to speak, subnets and has a high-tech hierarchy. In addition, it is impossible to imagine accessing a particular resource without a router that is able to choose the optimal path for faster access to a given resource.
And here is the interesting thing. The Internet as such does not have an owner, and the network itself is rather a virtual space that affects a person more and more every day, sometimes even replacing reality. For better or worse, it is not for us to judge. But let us dwell on the main aspects of the construction and functioning of the World Wide Web.
The structure of the global Internet: the history of appearance and development
As we know it today, the Internet has not always been. If you dig into the history, it should be noted that the first attempts to create a unified information network that could not only transmit data, but also serve as a kind of “translator” of many programming languages for the perception of information, were made back in 1962, in the very the height of the Cold War between the USA and the USSR. Then there was a program based on the theory of packet switching for data transfer Leonard Kleinrock, which was led by Joseph Liklider. The main direction was not only the transmission of information, but also its “indestructibility”.
Based on these developments, in 1969 the first network arose, called ARPANet, which became the progenitor of the Internet, or the World Wide Web. In 1971, the first program for sending and receiving e-mail was developed, by 1973, when the Euro-Atlantic cable was continued, the network became international, in 1983 it switched to a unified TCP / IP protocol, and in 1984 there was an IRC technology that allowed chatting . And only by 1989 at CERN did the idea of creating a global web mature, which is now commonly called the Internet. Of course, she was far from the model that is being used now, nevertheless, some basic principles that the structure of the Internet includes, and still have remained unchanged.
World Wide Web Infrastructure
Now let's see how it was possible to combine individual computer terminals and networks based on them into a single whole. The key principle was the use of packet data using routing based on a universal protocol that would be understandable to any machine. That is, information is not represented in the form of individual bits, bytes or characters, but is transmitted in the form of a formatted block (packet), which can contain quite long combinations of different sequences.
However, the transfer itself does not happen horribly. Moreover, the hierarchical structure and resources of the Internet have several basic levels:
- Highway (system of high-speed servers interconnected).
- Large networks and access points connected to the main trunk.
- Regional networks rank lower.
- Internet Service Providers (ISPs).
- End users
The structure of information on the Internet is such that the terminals on which it is stored are called servers, and the user (reading or receiving it, as well as sending feedback and streams) machines are called workstations. The transmission of the same information, as mentioned above, is based on routers. But such a scheme is presented solely for ease of understanding. In fact, everything is much more complicated.
Key Protocols
Now we come to one of the key concepts, without which it is impossible to imagine what the structure of the Internet is. These are universal protocols. Today there are a lot of them, but TCP / IP is the main one for the Internet.
In this case, it is necessary to clearly distinguish between two terms. The IP protocol (internetwork) is one of the means of routing, that is, it is solely responsible for the delivery of data packets, but in no way is responsible for the integrity and security of the transmitted information. The TCP protocol, on the contrary, is a means of providing session communication between the sender and the recipient on the basis of a logical connection between two points with the so-called guaranteed packet delivery, and it is absolutely intact.
Today, TCP / IP is the de facto Internet standard, although there are many other protocols such as UDP (transport), ICMP and RIP (routers), DNS and ARP (authentication for network addresses), FTP, HTTP, NNTP and TELNET (application ), IGP, GGP and EGP (gateway), SMTP, POP3 and NFS (mail and file access protocols on remote terminals), etc.
Domain Name System
Separately, it should be noted the universal approach to accessing resources. It is clear that writing a page address like 127.11.92.785 to get to the desired resource is not so convenient (and even more so remembering all these combinations). Therefore, at the time, a unique domain name system was developed, which allowed to enter the address in the form as we see it today (in English).
But here there is its own hierarchy. It also distinguishes several levels. For example, international top-level domains include resources that are independent of the country identifier (GOV - government, COM - commercial, EDU - educational, NET - network, MIL - military, ORG - general organizational, not relevant to any of the above types) .
The following are the domain names of the resources, which explicitly indicate the country identifier. For example, US - USA, RU - Russia, UA - Ukraine, DE - Germany, UK - Great Britain, etc. In addition, such domains have their own sublevels like COM.UA, ORG.DE, etc. turn, and here you can find a clearer binding at the levels of a lower rank (KIEV.UA, KIEV.COM.UA, etc.). In other words, when you look at the address, you can immediately determine not only the country, but also the territorial affiliation of the resource within it.
Basic Internet Services
As for the services that can be found on the Internet today, in their categories they are divided into e-mail, news and mailing lists, file-sharing networks, electronic payment systems, Internet radio and television, web forums, blogs, social networks, online stores and auctions, Wiki educational projects, video and audio hosting services, etc. Since social networks have become the most popular lately, let us dwell on their structure.
The structure of the social networks of the Internet
A common feature of such an online community is independence from territorial status or citizenship. Each user creates their own profile (image, place of residence on the Web, as you want to call it), and communication is carried out using the instant messaging system, but not through chat, but in private mode. With a chat you can only compare the comment system. In addition, any registered resident of such a community can leave the so-called posts, share with the public some materials or links to other publications, etc.
The structure of the Internet is such that when certain protocols are involved, such as TCP / IP and IRC, all this is done quite simply. The main condition is registration (creating a login and password for entry), as well as indicating at least minimal information about yourself.
It is not surprising that personal sites and chats are slowly but surely disappearing into oblivion. Even the once popular “dialers” like ICQ or QIP do not stand up to any competition, because social networks have much more opportunities.