Internet

INTERNET

The Internet is the global system of interconnected computer networks that uses the internet protocol suite to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business and government networks of local to global scope, linked by an array of electronic, wireless, and optical networking technologies. The internet carries a vast range of information resources and services, such as; the inter-linked hypertext documents and applications of WWW (World Wide Web), electronic mail, telephony, and file sharing.

Importance of Internet

Importance of Internet to Education

• Research: The Internet has a wide range of information that both teachers and students can access at the convenience of their locations. 
• Increase Accessibility of Education: Education is accessible now more than ever, thanks to the Internet. 
• Innovative Learning: The Internet offers extra resources and new methods of learning, Teachers can opt to have online classes which students attend from the comfort of their home. Alternative methods of learning and study materials also available on the Internet.
• Ease of Communication: Teachers and students can interact timely using Internet Platform. Most schools have online platforms where students hold discussion on various topics. 

Importance of Internet in Business-Organisation

1. Internal Communication: The Internet facilitate communication within organization especially those with branches in different geographical regions. Information from the head office reaches the rest of the branches promptly. Today e-mail is the main method of communication in many organizations.

Importance of Internet to Society

• Internationalization: The Internet facilities important international relationships and connections. These International interactions are important in trade, social exposure, cultural knowledge and embracing diversity. The Internet facilities the interaction between different countries and individuals from different nations withiut formal agreement.
• Globalization: As compared to Internationalization, globalization is more formal and focuses on the global economy. The Internet is crucial in establishing one global economy because it eliminates the physical boundaries that most avenues of business and Communication have. 
• Communication: Today, most people use the Internet primarily for the Communication. Facebook, Twitter, Instagram,  Most forms of communication including those on mobile phones require connectivity.
• Information Dissemination: Most of the people in the World today will Google something before they ask for help from other people. The saying that Internet has all answers is true, thanks to unlimited contents available online.

History of the Internet
The place to begin is the beginning -- and with the Internet, we need to go way back. Although the Web is the medium of the moment, the Internet has a long history and locating its origins depends on how primitive an ancestor you seek. 

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The thread of the development of the Internet stretches all the way back to 1958. The Internet's mother - the Organization that gave birth to it - was itself born in the contrail of Spuntik. In October, 1957, the USSR took the world by surprise by launching the first artificial satellite and made us the U.S. suddenly seem technologically backward. In response, President Dwight D. Eisenhower launched Advanced Research Project Agency (ARPA) as part of the Department of Defense in January, 1958.
The system began to assume its current identity with the first use of Transmission Control Protocol (TCP) in a network in July, 1977. As a demonstration, TCP is used to link together a packet ado network, SATnet, and ARPAnet. Then in early 1978, the TCP was split into a portion that broke messages into packets, resembled them after transmission, kept order among the packets, and controlled error control, called TCP, and a second protocol that concerned itself with the routing of packets through the linkage of the network, called the Internet Protocol (IP). The two together made TCP/IP, the fundamental protocol of today's Internet.
If the Internet actually has a birthday, it's January 1, 1983, when ARPAnet switched over from the Network Control Protocol to TCP/IP. To give a friendlier front end to communication with distant computer systems, Tim-Berners-Lee, working at CERN in Geneva in 1990, invented the WWW (World Wide Web).
The final step in the today's Internet came in 1991. In that year the National Science Foundation, which was overseeing the operation of the Internet, lifted its previous restrictions on its commercial use. The free-market free-for-all began.



IP Address

Under the Internet Protocol, an address is four bytes, a 32-bit binary number. Usually you will find it expressed as a series of four numbers called octets. The value of each octet is expressed in decimal notation, and the individual octets are separated by periods. Hence, an Internet address looks like this:
162.233.12.135

Every device get its own unique address.  Do the math, and you will see the scheme allows for 4,294,967,296 unique devices (which is simply 2 to the 32nd power, exactly what a 32-bit binary address means).


Addresses you can't use

The IP naming rules dictate that you cannot use certain addresses for computers on a network. These falls at the two ends of a number range in the fourth octet. This is, address ending in zero, such as 192.168.155.0, and those ending in 255, such as 192.168.254.255, cannot be used as address for the computer and other devices connected to a network. These addresses have specifically defined meaning in the IP system.
Addresses ending in zero refer to a network itself rather than any specific computer or device connected to it. Addresses ending in 255 are used to broadcast messages to all devices in a network will receive packets with with the network address and a 255 at its end. 
The Rule is simple: Never use these addresses when assigning IP addresses to any device in your network.

 

DHCP (Dynamic Host Configuration Protocol)

Using the Dynamic Host configuration Protocol (DHCP),  you can move the responsibility for assigning and organizing the IP addresses your network uses to one of its server.
DHCP is an automatic method for assigning addresses to devices. When a device wants to join the network, it queries the DHCP server, and the server sends back the unique code. 
Note that you should have only one DHCP server in a network. If you install a dedicated server to act as your DHCP server and you install a router for Internet sharing, the two DHCP servers may come  into conflict, possibly preventing your network from operating, or just preventing some computers from seeing others on the network.


Web pages

The World Wide Web is the most visually complicated and compelling aspects of the Internet. Despite its appearances, however, the Web is noting more than an another file transfer protocol. When you call up a page from the Web, the remote server simply downloads a file to your computer. Your Web browser than decodes the page, executing commands embedded in to alter the typeface and to display the images at the appropriate place.

HTML

The commands for displaying the text use their own language called the HTML (Hyper Text Markup Language). HTML is a coding system that combines formatting information in textual  form with the readable text of a document. Your browser reads the formatting commands, which were set by a special prefix so that the browser know that they are command and organizes the text in accordance with them, arranging it on the page, selecting the appropriate font and emphasis, and intermixing graphic elements. Writing in HTML is only a matter of knowing the right codes and where to put them. Web authoring tools embed the proper commands using menu-driven interfaces so that you don't have to do memorization.


Service Providers

In truth, the Internet was not designed to link Computers but rather to tie together Computer Networks. As its name implies, the Internet allows data to flow between networks. Even if you only have a single Computer,  when you connect with the Internet, you must run a network protocol the same a if you had slung miles of Ethernet Cable through your home and office. Weather you like it or not, you end up tangled in the web of networking when you connect to the Internet.

Security

The Internet is not just a means of moving messages between computers. It was designed as a link between computer. It was designed as a link between computer systems that allowed scientists to share machines. Command for Computer System move across wires just as easily as Words and Images. 
A Computer Virus is a program code added to your computer without your permission. A computer virus cannot represent by itself -- It takes command of your computer and uses its resources to duplicate itself. Computer viruses are contagious in that they can be passed along from one machine to another. But computer viruses are noting more than digital code, and they are machine specific.
Virus get into your Computer because you let them. They come through any connection your computer has with the outside world, including floppy disk and going online. Browsing web pages ordinarily won't put you at risk because HTTP doesn't pass along executable programs. Plug-ins may, however. Whenever you download a file, you run a risk of bringing a virus with it. Software and drivers that you download are the  most likely carriers. Most Webmasters do their best to ensure that they don't pass along the Viruses. 
However, you should always be wary when you download a program from a less reputable site. The same warning applies e-mail from unknown senders.




Writer: Mr. Krishan Kumar Saini

Today We have learnt about the Internet. Hope this lesson is helpful for you.