How the Internet works?

   The Internet originates somewhere in the 60's, in ARPANET and NSFNET. The Internet is made up of a lot of connections that are created between the server (source) and users, of course, no one foresaw how this shift from a military network to a public and commercial one will affect our way of thinking about information and communication between us.

   

   During the 1960s, the US Department of Defense needed a communication network in the event of a nuclear attack. RAND, a military corporation, has proposed centralizing communications in a network. This network contained nodes capable of transmitting and receiving messages. Each node has its own address so that the message could transmit a particular node. The Defense Department's Advanced Research Projects Agency known as ARPA or DARPA has decided to expand this network. In 1969, the first "Interface Message Processor," the predecessor of today's router, was installed at UCLA (University of California in Los Angeles) that ARPANET was expanding. ARPANET includes several services that are today very important in today's Internet, such as FTP (File Transfer Protocol), remote login (TELNET) and E-mail (electronic mail). While ARPANET is starting to grow, companies like Xerox are developing local area network (LAN).

  

   The network with the most impact was Ethernet, a network that allowed multiple computers to connect together. The first version had a theoretical transfer rate of 3 Mbps and later 10 Mbps. ARPANET researchers began believing it would be useful to connect LANs to ARPANET. To achieve this, a protocol has been developed to connect different types of equipment. So Transmission Control Protocol (TCP) and Internet Protocol (IP). In 1983, Internet growth was boosted by the release of the 4.2x BSD version of UNIX that included the TCP / IP protocol.

   

   To understand how the Internet works, you must understand that the Internet is not a homogeneous entity. Indeed it is a great miracle that still works. The Internet has a structure, so if you want to send an E-mail to your neighbor's computer, the message has to cross hundreds of miles. Moreover, the cars that are connected have not been built to communicate directly with each other. And yet the Internet works.

   

   The starting point for everyone on the Internet is the ISP (Internet Service Provider). An ISP may be commercial, or a school, or a college, university, etc. Some users can be connected to the LAN, others can access the Internet using a modem and a PPP or SLIP connection. All ISPs are connected to the Internet through other ISPs. At the bottom level, a local ISP is connected to another local ISP. The next level is ISPs that connect with other ISPs outside, and so on.

Routers, what are they?

   

    As your request finds its way to a site and how information finds its way, it is determined by two things: TCP / IP routers and protocols. Routers (sometimes called gateways) are similar to phone operators. They connect the networks to each other and have tables to determine how information flows from and to the Internet. Routers have an IP for each connection, for example a router that has a PPP connection and two ETHERNET connections, should have 3 IPs. The secret that makes the Internet go is the TCP / IP protocol. IP is the component that moves data packets to one network node to another. TCP is the component that checks if the data has arrived right.

Let's talk about "WWW", all we need to know about it:

     

   The World Wide Web (also known as WWW, W3, or the Web) has made internet access to information for a regular person much easier. The WWW is the Internet service that has developed the most in recent years (and which is the most used). On the Web you can find information about a culinary recipe or how to make a thermonuclear bomb, virtually all the knowledge of mankind is gathered there.

   

   Strictly speaking, the WWW is a system for accessing hypertext on the Internet. It is made of documents, images, sounds and links to other documents or servers. A Web document may also contain links to other services such as FTP, Gopher, Archie, Telnet, etc. A better way to look at the Internet is to see it interactively, to have a graphical interface, to be easy to use. You can search for information about any subject. You can find out about the latest research in the field of artificial intelligence or read your favorite newspaper. Moreover, to access this information you do not have to know any special commands or codes, just a simple click to access that information. The WWW was launched in 1989 as the European Laboratory for Particle Physics (CERN). Tim Berners-Lee proposed a protocol to be used to distribute information on physics on the Internet, a protocol that will be adopted by other organizations. The most important reason why WWW can work on different types of computers is HyperText Transfer Protocol Secure (https). Https is the standard set of commands that allows secure Internet communication. Without HTTPS, the browser you are using does not know if the information that came is HTML or a document, program or VRML environment.

   
   In conclusion, the Internet has become the most widely used transfer method for data and information, and it will evolve more and more in the coming years.