GETTING CONNECTED TO INTERNET!
From a technical point of view the Internet is a collection of thousands of networks, distributed throughout the world, that agree to communicate using certain rules or protocols.Each site on the Internet has a unique numeric address called its IP address and usually a corresponding name called the domain name. Information is passed around the Internet in packets. Each packet contains the address of the sender and the address of the destination.
A Video about How the Internet Works!
IP Address:
Every computer on the Internet is identified with an address, called Internet Address or Internet Protocol Address (IP Address). IP Address is a number that uniquely identifies each computer on the net. Each of these addresses is of four bytes. Each byte is used for forming an integer. The numbers are ranging from 0 to 255 in decimal (i.e., 00 to FF in hexadecimal).
The four numbers in an IP address are separated by dots in between them. Hence, an IP address is written as, for example, 150.80.0.231. We often refer to them as a sequence of four numbers between 0 and 255 separated by dots (.). This makes them easier to number, because they are not randomly assigned, but hierarchically assigned.
Client/Server Model:
Many of the services operate according to a client/server model. A program called the client (for instance, web browser) is started on one system and contacts a program called the server (for instance, IIS or Apache) at another computer on the Internet. The client sends the commands typed or given by a user to the server. The server sends a reply to the client, and the client presents the information to the user.
All information on the Internet is in digital format. This includes text, programs, charts, images, graphics, video, and audio. When using the WWW we work in a hypertext or hypermedia environment.
A Uniform Resource Locator (URL) specifies items, services, and resources. These are used by Web browsers to specify the type of Internet service or protocol to use and the location of the item.
Uniform Resource Locator:
Uniform Resource Locator (URL) is one type of Internet address, using which we can specify the address (i.e, location) of a web page. Each web page on the Internet is associated with a unique URL. URL usually begins with http://, which stands for Hyper Text Transfer Protocol, the industry standard for transferring web documents over the Internet.
The URL for the Web page "Abraham Lincoln: Internet Resources from the Library of Congress," for example, is http://lcweb2.loc.gov/ammem/alhtml/alrel.html. The protocol or service in this case is HTTP, or Hypertext Transfer Protocol, and a Web browser using it would contact the Internet site lcweb2.loc.gov and access a document named alrel.html. The documents on the WWW are called Web pages. These are written and constructed using a language or set of rules called Hypertext Markup Language (HTML).
The URLs of the web sites that handle private information, such as credit card number, often begin with https://, which is the abbreviation for Secure Hyper Text Transfer Protocol (https), the standard for transferring encrypted data over the Internet.
Basic requirements for Internet:
To get connected to the Internet, we need a connecting device such as modem or Network Interface Card (NIC) and a connection to an Internet Service Provide (ISP). A Modem is a hardware that enables a computer to connect to the Internet. Its primary task is to convert the digital data to audio tones that can be sent transmitted over the phone lines. The received analog data are then converted back to the digital data for further processing.
A Network Card, also called Network Interface Card (NIC) is a hardware that allows a computer to connect to the Internet through a network or a high-speed internet connection, such as Local Area Network (LAN), cable modem or Digital Subscriber Line (DSL). After ensuring that our computer has a modem or a Network Interface Card, the next step is to register with an Internet Service Provider (ISP).
Now, we can access the Internet by having a direct connection from our computer to a network. This is often the case when our company or campus has a network installed in offices, classrooms, labs, or residence hall rooms. To get connected to the Internet we’ll need the proper device to connect to our organization’s network and (possibly) the IP address for our computer and for a domain name system.
Another way to connect to the Internet is to use a modem to call an Internet service provider (ISP) and gain access through a PPP (Point-to-Point Protocol) connection. In either case you may have to configure an email client and Usenet news client to handle incoming and outgoing email and reading and posting messages to Usenet newsgroups.
Dial-up Connections:
Dial-up connections are slow internet connections that make use of existing telephone lines for transmission. If a computer is connected to the Internet using this type of inter connection, the user can’t receive voice calls via the telephone line while accessing the net. If the voice calls do connect, the Internet connection is interrupted. To prevent this, users often install an extra phone line dedicated to Internet service.
Broadband Connections:
Bandwidth refers to the amount of data that can be transferred through a communication medium in a fixed amount of time. Different ISPs offer different types of high-speed connections, called broadband connections, which include DSL, cable modem and Integrated Services Digital Network (ISDN), each of which has a different bandwidth.
Broadband connection is a high-bandwidth Internet service that is most often provided to home users by cable television and telephone companies. DSL is one type of broadband service that allows computes to have access to the Internet all the time through existing phone lines, without interfering with telephone services. However, DSL requires a special modem provided by the ISP.
Like DSL, cable modems also enable the computer to access the Internet at all times. Cable modems transmit data over the cables that bring television to homes and business. Unlike DSL, the bandwidth is shared by many users in cable modem. This sharing can reduce the bandwidth available to each user when many use the Internet simultaneously.
ISDN is also a broad-band connection, which provides Internet service over either digital or standard telephone lines. To avail this type of high-speed connection, we need to have a special hardware, called a Terminal Adaptor (TA), which is usually obtained from the IP.
