01 intro to internet (re-upload)
- 2. Structure and Nature of Internet- An Introduction Information and communication are the major sources for the development of a society or an individual. Faster means of communication and information transfer are available today. Think out the ways you generally use: •Oral- Example: Talk to a friend •Written- Example: Write a letter •Digital- Example: Send an SMS What would you do in the following situation? Your manager has been to Delhi to attend an important meeting and he asks you to send some files immediately. How would you send them at an earliest? Yes, the most possible solution today is using the Internet.
- 3. Structure and Nature of Internet- What is Internet? The Internet is a large network of systems interconnected with each other. Internet offers a variety of services and tools. Today, people across the world interchange lot of information called ‘data’ using the Internet. The most common uses of the Internet are sending and receiving e-mails, chatting, searching for information, etc. Terms you should know: Intranet: Extranet: An Intranet is the private networking An Extranet is actually an Intranet system within an organization. You that is partially accessible to can simply define it as a private authorized outsiders. Simply, it is an internet. Intranet serves as powerful extended Intranet to the users tool of communication in an outside an organization. People who organization. are not related to the organization cannot access the information.
- 4. Modem stands for MOdulator/DEModulator. Structure and Nature of Internet- Connection Requirements The basic requirements to get an Internet connection are: • Modem stands for •a computer MOdulator/DEModulator. A modem is a device that • a phone-line enables a computer to transmit data over phone or cable • a modem • ISP stands for Internet Service • an ISP Provider. An ISP can be company offering its clients to access the Internet. There are different types of internet connections available today. The requirements to connect to the Internet change based on the type of connection you choose.
- 5. Structure and Nature of Internet- Connection Requirements Continued… Following are some common types of Internet connections: Dial-up: The ‘Dial-up’ connection is mostly preferred for domestic purposes. Requirements: a phone-line, modem, and an Internet Service Provider (ISP). The typical Dial-up connection speeds range from 2400 bps to 56 Kbps. Cable: Through the use of a cable modem you can have a broadband Internet connection that is designed to operate over cable TV lines. The cable connection speeds range from 512 Kbps to 20 Mbps. Wireless: Wireless Internet, or wireless broadband is one of the newest Internet connection types. Instead of using telephone or cable networks for your Internet connection, you use radio frequency bands. The wireless speeds range from 1.6 Mb/s 66 GHz. Generally, we choose the type of connection based on our domestic or business requirements.
- 6. Structure and Nature of Internet- How do computers talk to each other? Answer the following: Who brings you the letters? How do they reach you instead of going to someone else? You are right! A postman brings them to you based on the door number in the address. Similarly, your computer requires a Gateway which brings you the information based on the Internet Protocol address of your computer. Gateway IP Address A gateway is a node (a router) Each computer (known as a on a computer network that host) on the Internet has at serves as an access point to least one IP address that another network. This node is uniquely identifies it from all capable of sending, receiving, other computers on the or forwarding information over Internet. a communications channel.
- 7. Structure and Nature of Internet- How can a computer use the telephone line? If you have a telephone-line, you can access to the Internet through a ‘Dial-up’ connection. What if I don’t have a computer? Using a modem connected to your PC, users connect to the Internet when the computer dials a Advancement in technology has made access to internet even phone number (which is provided by your ISP) much easier. You can get and connects to the network. In ‘Dial-up’ connected to the Internet if your connections, data is sent over public telephone mobile has the GPRS (General network. Packet Radio Service) option. Your mobile acts as a mini The modem converts the data to digital and vise computer. versa. However, dial-up connection is slow as it uses the normal telephone lines. Also the data rates are limited.
- 8. How is a computer address different from a phone number when their purpose is the same? You talk to a person using a phone. But using a ‘Dial-up’ connection, you start interacting with another computer using your computer. Also the format of a phone number and an IP address vary. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 192.168.1.28 could be an IP address.
- 9. How do I get an address for my computer and start working on the computer? You can contact your ISP once you have all the requirements in place. Your ISP provides you the basic information for accessing the Internet such as the Gateway and IP address allotted to your computer. If you want to connect to the Internet, you have to do the following: • Configure a Dial-up Networking (DUN) • Dial your Point of Presence (POP) • Log into your Internet Service Provider (ISP)
- 10. Using Internet
- 11. Using Internet- The World Wide Web In the previous section, you have learnt about the different Internet connection types and their requirements. In this section, you will learn about the basics and the effective ways of using the Internet. Do you know what is WWW? Yes, WWW is the short form of the World Wide Web. In short we call it the Web. Tim Berners-Lee, a scientist at CERN, invented the World Wide Web (WWW) in 1990. The basic idea of the WWW was to merge the complex Internet technologies into easy to use global information system.
- 12. Using Internet- Web Browsers A web browser or browser is a software application that helps you to browse or locate and display the Web pages. These Web pages may contain text, images, music, videos, games, etc. The most common Web browsers are: Internet Explorer Mozilla Firefox Google Chrome Safari Opera Netscape
- 13. Using Internet- Web Browsers Continued… You can install these software applications on your computer system. After the installation is complete, you can find a small browser icon on your desktop. Next time when you want to open the browser, you can simply click on the icon. Following is an image of a Web browser window:
- 14. Using Internet- Navigating Across the Web Pages You have already learnt that a browser helps you to locate the Web pages. Let’s have a glance of the main features of a browser window that help you to locate as well as navigate across the Web pages. Type the URL of a website in the address bar and press Enter. Navigation and Reload Buttons The Status bar displays the status of the page being loaded. The Menu bar options help you work with different setting options.
- 15. Using Internet- Opening Web pages using URLs Recall when you first visited your friend’s house. You could easily locate his house with the help of the address. Similarly, you need to provide the URL (Uniform Resource Locator) of a website in the browser’s address bar. Example of a URL: Understanding the URL: • http stands for Hypertext Transfer protocol which is a request/response between an end user (you) and the server (Web site). http remains common for most of the websites. URLs that start with https denote to be a secure website. • google.co.in stands for the domain name. This name is followed by a slash (/) if you intend to open a page within the domain name. So you need to have a proper URL of a Web site to open it in a browser.
- 16. Using Internet- Opening linked pages How do you open a specific chapter in a text book? Yes, you can find a list of chapters and their page numbers on the Index page. A website also has several pages. And it’s very easy to open the pages you want to see when compared to a text book. Let’s see how: Observe the text on a Web page. Some words are underlined in color. Some words or images change their colors when you move the mouse over them. The cursor also changes to a pointer icon. Such words or images are linked to the pages which have the information related to them. These words or images, called Hyperlinks, make navigation across the pages of a Web site easy.
- 17. Searching
- 18. Searching- Search Engines We search for something when we don’t know its exact location. Likewise, if you don’t know the URL of a specific Web site, you have to search for it. You cannot use a browser’s address bar to search for the information or a Web site. Then, how do I search for any information? There are tools called Search Engines which help you to locate the information you want. Following is an image of some common types of search engines: