Class 11 Computer Science Chapter 10 Notes

• Describe brief early history of the Internet.
• In 1969, Advanced Research Project Agency (ARPA) established a small computer network among different universities and defense organizations. The goal was to establish a large computer network that could survive in war times. Initially ARPANET was a wide area network connecting a small number of users. There were only four hosts (A host is a computer that provide services to other computers of the network). But the network grew rapidly and spanned over countries. Meanwhile another research organization, National science foundation, joined the project. NSF established five supercomputing centers which were available to all researchers for academic purposes. To provide high speed access to supercomputers, NSF established a separate high speed network called NSFnet. During this period, some other small networks had also been established among various universities and organizations. The authorities decided to link ARPANET, NSFnet and other small networks so that they can communicate each other. This link among different networks is referred to as the Internet.
• Describe how Internet Works.
• Describe Addressing Scheme? Explain the two types of Addressing Schemes.
• Explain Web Browsing.
• Explain World Wide Web (WWW).
• Explain URL (Uniform Resource Locator).
• Explain Search Engine.
• Explain Email? Describe Limitations of Email.
• Explain Email Address.
• Explain Newsgroups. 
• In 1969, Advanced Research Project Agency (ARPA) established a small computer network among different universities and defense organizations. The goal was to establish a large computer network that could survive in war times. Initially ARPANET was a wide area network connecting a small number of users. There were only four hosts (A host is a computer that provide services to other computers of the network). But the network grew rapidly and spanned over countries. Meanwhile another research organization, National science foundation, joined the project. NSF established five supercomputing centers which were available to all researchers for academic purposes. To provide high speed access to its supercomputers, NSF established a separate high speed network called NSFnet. During this period, some other small networks had also been established among various universities and organizations. The authorities decided to link ARPANET, NSFnet and other small networks so that they can communicate each other. This link among different networks is referred to as the Internet.
• How the Internet Works: The Internet is a huge collection of millions of computers, all linked together on a computer network. The network allows all of the computers to communicate with one another. A home computer may be linked to the Internet using a phone-line modem, DSL or cable modem that communicates to an Internet service provider (ISP). A computer in a business or university will usually have a network interface card (NIC) that directly connects it to a Local Area Network (LAN) inside the business. The business can then connect its LAN to an ISP using a high-speed phone line like a TI line. A TI line can handle approximately 1.5 million bits per second, while a normal phone line using a modem can typically handle 30,000 to 50,000 bits per second. ISPs then connect to larger ISPs, and the largest ISPs maintain fiber-optic "backbones" for an entire region. Backbones around the world are connected through fiber-optic lines, undersea cables or satellite links. In this way, every computer on the Internet is connected to every other computer on the Internet.