Notes: Basics of Internet - 1

Table of Contents
1. Introduction
2. How the Internet Works
3. Who governs the Internet?
4. Connection to the Internet
5. Internet Functions
6. Web Browser
7. E-mail Concepts
8. Applications of the Internet
View more

Introduction

The Internet is a global network connecting millions of computers across the world. It enables users to share information, communicate, and access resources seamlessly. It is also known as a "network of networks," consisting of millions of private, public, academic, business, and government networks. It evolved from the ARPANET (Advanced Research Projects Agency Network), developed in 1969 as the first packet-switching network.

How the Internet Works

Most computers on the Internet are not directly connected to each other. Instead, they connect through Internet Service Providers (ISPs) that route data between devices using a series of networks and gateways.

• Gateway: A gateway is a device that connects dissimilar networks and facilitates communication between them.
• Router: A router directs data packets between networks, determining the most efficient path.
• Modem: A modem converts digital signals from a computer into analogue signals suitable for transmission over telephone or cable lines and vice versa.
  

Who governs the Internet?

The Internet is not governed by any single organisation. Instead, it is coordinated by several volunteer organisations.

• The Internet Architecture Board (IAB) is responsible for approving standards and allocating resources.
• The Internet Engineering Task Force (IETF) discusses and investigates operational and technical problems of the Internet.
• The InterNIC provides registration services to the Internet community.

Connection to the Internet

• Through Dial-up Connection: A dial-up connection is a temporary link established between your computer and the ISP (Internet Service Provider) server. It uses a modem to dial the ISP server number via a telephone line.
• Through Broadband Connection: Broadband refers to high-speed Internet connections that can transmit data at much higher rates than dial-up connections, which refers to the amount of data a signal or circuit can carry. Broadband connection speeds are measured in megabits per second (Mbps).
• A Wireless Connection: These days, Internet access can also be wireless.
• Wi-Fi: Wireless Fidelity (Wi-Fi) allows you to connect to the Internet without a direct cable from your PC to the ISP.
• WiMAX: WiMAX is a wireless digital communication system that can provide broadband wireless access (BWA) over distances up to 50 km for fixed stations.

Internet Functions

The Internet provides various functions that allow users to communicate, exchange information, and collaborate globally. These include:

• E-mail: Sending and receiving electronic messages.
• World Wide Web (WWW): Developed by Tim Berners-Lee in 1989, is a collection of interlinked hypertext documents that can be accessed through the Internet. These multimedia pages are dynamic and regularly updated.
• File Transfer Protocol (FTP): Transferring files between computers.
• Chat and Instant Messaging: Real-time communication between users.
• Video Conferencing: Conducting meetings over the Internet using video and audio.

Web Browser

A web browser is a software application that enables users to access and view web pages on the Internet. Examples include Google Chrome, Mozilla Firefox, Microsoft Edge, and Safari.

Key Elements of a Browser Window:

• Address Bar: Displays the Uniform Resource Locator (URL) of a web page.
• Back and Forward Buttons: Used to navigate between previously visited pages.
• Refresh/Reload Button: Reloads the current page.

Various features of a Web Browser:

• Menu bar: Located at the very top of the screen, accessed using the mouse. Actions shown in black can be performed; those in grey or lightened cannot.
• Toolbar: Positioned below the menu bar, it contains navigation buttons for the Web with basic functions such as back, forward, refresh, and home.
• Location bar: Below the toolbar, this box (sometimes labelled "Location," "GoTo," or "Address") allows you to type a website's URL and press Enter to open the site.
• Status bar: Found at the bottom of the browser window, it shows the progress of web page downloads, indicating if the host computer has been contacted and if text and images are downloading.
• Scroll bar: The vertical bar on the right side of the browser window, used to scroll up and down a web page by dragging the slider.
• A website is a set of related web pages served from a single web domain.

Uniform Resource Locator (URL)

A URL is the address of a resource on the Internet. Example: https://www.ugcnetonline.in

Each part of a domain name provides information about the hierarchy:

• Top-Level Domain (TLD): .com, .org, .gov, .edu, etc.
• Second-Level Domain: The main name chosen by the organisation or individual.
• Subdomain: A subdivision of the main domain (e.g., mail.example.com).

• The hyperlink is a reference to data that the user can follow directly by clicking, hovering, or automatically.

E-mail Concepts

E-mail (Electronic Mail) is one of the most widely used Internet services. It allows users to send and receive messages instantly across the world. The first email was sent by Ray Tomlinson to himself in 1971.

• CC (Carbon Copy) in an email indicates recipients who receive a copy of a message addressed primarily to others. The list of CCed recipients is visible to all recipients.
• An additional BCC (Blind Carbon Copy) field allows hidden notification; recipients in BCC receive a copy but are not shown to other recipients (including other BCCs).
• An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) on a network. It serves as a unique identifier for each computer. There are two versions of IP addresses in use: IPv4 (32-bit) and IPv6 (128-bit).
• Top-level domain: Each part of a domain name contains specific information. The first field is the hostname, identifying a single computer or organisation. The last field is the top-level domain, which describes the type of organisation or country of origin. 
  For example: .com - Commercial, .edu - Education
  

Applications of the Internet

Today, there is an Internet application for nearly every task, making work easier and more efficient.

Various Applications of the Internet are:

• Exchange messages using e-mail (Electronic mail).
• Transfer files as well as software.
• Browse information on any topic on the web.
• Communicate in real time (chat) with others connected to the Internet.
• Search databases of governments, individuals, and organisations.
• Read news available from leading newsgroups.
• Send or receive animation and picture files from distant places.
• Set up a site with information about your company's products and services.