The Internet has become an indispensable part of our lives, connecting people, information, and services across the globe. In this article, we will delve into the origins and development of the Internet, understand the differences between Internet, Intranet, and Extranet, and explore the various modes of connecting to the Internet.

The History of the Internet

The Internet has its roots in the 1960s when the Advanced Research Projects Agency Network (ARPANET) was developed by the United States Department of Defense. Initially designed for military purposes, ARPANET later evolved into a network that connected academic and research institutions. The invention of the World Wide Web by Sir Tim Berners-Lee in the late 1980s revolutionized the way we access and share information on the Internet.

Understanding the Internet, Intranet, and Extranet


The Internet refers to the global network of interconnected computers and devices that use standardized communication protocols. It allows users to access and exchange vast amounts of information through websites, email, file sharing, and other online services.

Definition and Functionality

The Internet serves as a vast digital infrastructure that enables communication, collaboration, and access to resources worldwide. It operates on a decentralized model, with no single governing authority. Instead, it relies on a distributed network of servers, routers, and cables to transmit data packets between connected devices.

Connecting to the Internet

To connect to the Internet, individuals and organizations require an Internet Service Provider (ISP). ISPs provide users with access to the Internet through various technologies, including broadband, DSL, or fiber optics. Users can connect using wired or wireless methods, depending on their preferences and availability.


An intranet is a private network that uses Internet technologies to share information, resources, and services within an organization. It functions similarly to the Internet but is restricted to authorized users within the organization.

Definition and Purpose

An intranet acts as an internal communication and collaboration platform, enabling employees to access company-specific information, documents, and applications. It enhances productivity, facilitates knowledge sharing, and streamlines internal processes within an organization.

Benefits of Intranet

The benefits of an intranet include improved communication, enhanced information sharing, increased employee engagement, and streamlined workflows. It provides a centralized hub for employees to access company news, policies, and resources, fostering a sense of unity and connectivity.

Examples of Intranet Usage

Many organizations utilize intranets for various purposes, such as employee onboarding, project management, document sharing, and internal communication. Intranets often incorporate features like discussion forums, document repositories, employee directories, and collaborative workspaces.


An extranet extends the concept of an intranet to include authorized external parties, such as clients, suppliers, or business partners. It enables secure collaboration and information sharing between an organization and its external stakeholders.

Definition and Applications

An extranet provides a controlled and secure environment for external entities to access specific information, collaborate on projects, and conduct business transactions with the organization. It strengthens relationships, improves efficiency, and streamlines communication between the organization and its external partners.

Collaborating with External Parties

With an extranet, organizations can share project-related documents, exchange data, and provide limited access to their systems for external parties. This facilitates seamless collaboration, enhances transparency, and fosters stronger partnerships.

Modes of Connecting to the Internet

Wired Connections

Wired connections utilize physical cables to establish a connection between a device and the Internet.


Ethernet is a common wired technology used to connect devices to a local network or directly to the Internet. It provides reliable and high-speed connectivity, typically through Ethernet cables or Ethernet over Powerline (EoP) adapters.


Digital Subscriber Line (DSL) utilizes existing telephone lines to transmit digital data. It offers faster speeds compared to traditional dial-up connections and is widely available in many areas.

Fiber Optics

Fiber optics uses thin strands of glass or plastic to transmit data using pulses of light. It offers the fastest and most reliable wired connection, capable of delivering high-speed Internet access.

Wireless Connections

Wireless connections allow devices to connect to the Internet without the need for physical cables.


Wi-Fi is a wireless networking technology that enables devices to connect to a local network or access points wirelessly. It is widely used in homes, offices, and public spaces, providing convenient and flexible Internet access.

Cellular Data

Cellular data, also known as mobile data, allows devices to connect to the Internet using cellular networks provided by mobile service providers. It enables Internet access on smartphones, tablets, and other mobile devices, even while on the move.


Satellite Internet utilizes satellites in Earth’s orbit to establish a connection between the user and the Internet. It is often used in remote areas where wired or cellular connectivity is limited.



Give an introduction to the Internet and its history. Specify the distinction between Internet, Intranet and Extranet. What are the various modes of connecting to the Internet?


Answer the following questions in brief :
(a) What is the role of ISPs in the Internet?
(b) Describe the addressing Hierarchy used in the Internet.
(c) Explain the purpose of DNS in the Internet.


(a) What is the role of HTTP and Web Browsers in the World Wide Web? Name some common Web Browsers in use nowadays and give details of any two.
(b) Explain in detail how searching is carried out in WWW using search engines.


Give a brief description of the following :
(a) Telnet and FTP.
(b) HTML.
(c) TCP/IP


(a) What are the various components of E-mail architecture? Describe the protocols used in E-mail. What is MIME? List the headers defined by MIME.
(b) What is the advantage of using mailing lists? How does the newsgroup service differ from the mailing list facility?


(a) What is the basic structure of HTML documents? List some important tags used in HTML along with heir purpose.
(b) Provide a brief introduction of XML, DHTML, and JavaScript along with the purpose for which they are used.


What are Web Servers? Describe the accessing and using of any one server of your choice.


(a) Describe the various encryption schemes than can be used to secure data.
(b) What is the purpose of Digital Signatures and Firewalls in Internet security?