The Internet, often referred to as the “Information Superhighway,” is a global network that connects millions of devices and facilitates the exchange of information and resources across the world. It has revolutionized the way we communicate, access information, and conduct various online activities. In this article, we will explore the concept of the Internet, distinguish it from an intranet, and provide a comprehensive overview of how it works.
Introduction
In today’s digital age, the Internet has become an essential part of our lives, enabling us to stay connected, access a vast range of information, and engage in various online activities. From communication and entertainment to education and business, the Internet plays a pivotal role in shaping our modern society.
Definition of the Internet
The Internet is a global network of interconnected devices, including computers, smartphones, tablets, and servers. It enables the transfer of data, communication, and the sharing of resources through a standardized set of protocols, primarily the TCP/IP (Transmission Control Protocol/Internet Protocol). This allows devices from different locations and networks to communicate and exchange information seamlessly.
Difference between Internet and Intranet
While the terms “Internet” and “intranet” are often used interchangeably, they represent distinct concepts with different purposes and scope.
The Internet is a public network that spans the globe, connecting devices and networks worldwide. It provides access to a vast array of information, services, and resources available to the general public. Examples of the Internet include websites, search engines, online marketplaces, social media platforms, and more.
On the other hand, an intranet is a private network confined within a specific organization or a group of users. It allows authorized individuals within the organization to access internal resources, collaborate, and share information securely. Intranets are commonly used by businesses, educational institutions, and government agencies to enhance internal communication and facilitate efficient sharing of data among employees or members.
To illustrate the difference, let’s consider an example: Imagine a company called ABC Corp. ABC Corp. has an intranet that only employees can access. The intranet contains internal documents, employee directories, and company-specific applications. However, when these employees want to browse the web or access external resources, they need to connect to the Internet, which is a separate network accessible to the public.
Working of the Internet
To understand the working of the Internet, let’s explore its key components and mechanisms:
a.) End Systems and Routers
End systems, also known as hosts, are devices that directly interact with users and connect to the Internet. These include personal computers, laptops, smartphones, tablets, and other devices capable of running network applications. End systems utilize various software applications, such as web browsers, email clients, and instant messaging services, to communicate and access the Internet.
For example, when you open a web browser on your laptop or smartphone and enter a website’s URL, your device acts as an end system. It sends a request to the Internet to retrieve the desired web page, and once the data is received, the web browser renders the page for you to view.
Routers, on the other hand, are devices responsible for forwarding data packets between networks. They examine the destination address of incoming data packets and determine the most efficient path to transmit the packets to their intended destinations. Routers play a vital role in directing data through the complex network infrastructure of the Internet.
Let’s consider an analogy: Think of end systems as individual homes in a city, and routers as the intersections and roads connecting these homes. Just as routers direct traffic efficiently to reach specific destinations, Internet routers ensure that data packets reach their intended destinations by selecting optimal paths through the network.
b.) Backbone and Access Network
The Internet backbone refers to the high-speed, high-capacity communication links and routers that form the core infrastructure of the Internet. These backbone links are typically operated by major telecommunications companies, internet service providers, and governmental organizations. They interconnect various networks and provide the necessary bandwidth to transmit large volumes of data across vast distances.
For instance, major fiber-optic cables, such as undersea cables connecting continents, are part of the Internet backbone. These cables enable the global transmission of data, ensuring connectivity between different regions of the world.
Access networks, on the other hand, provide the final link between end systems and the Internet backbone. They allow individual users or organizations to connect their devices to the Internet. Access networks can utilize various technologies depending on the availability and infrastructure in a particular location. Some common examples include:
- Digital Subscriber Line (DSL): This technology uses existing telephone lines to provide internet connectivity. It allows users to access the Internet while simultaneously making voice calls.
- Cable Modem: Cable internet utilizes the same coaxial cables that deliver cable television. It offers high-speed internet access by leveraging the cable infrastructure.
- Fiber-optic Connection: Fiber-optic cables use light signals to transmit data, offering extremely fast and reliable internet connections. Fiber-optic internet is known for its high bandwidth and low latency.
- Wireless Connections: Technologies such as Wi-Fi, satellite internet, and cellular networks provide wireless access to the Internet. These connections are convenient for users who require mobility or reside in areas where wired connections are impractical.
c.) ISP (Internet Service Provider)
Internet Service Providers (ISPs) are commercial entities or organizations that offer internet access to end users. They play a crucial role in connecting individuals, businesses, and institutions to the larger Internet. ISPs invest in the necessary infrastructure, such as servers, routers, and network equipment, to provide reliable and high-speed internet connectivity.
ISPs offer a range of internet connection options, including broadband, DSL, cable, and wireless, catering to the diverse needs of users. Users subscribe to an ISP’s services and gain access to the Internet through the ISP’s network.
To illustrate, let’s consider a scenario: If you subscribe to a broadband internet service from XYZ ISP, the ISP would provide you with the necessary equipment (such as a modem or router) and establish a connection between your end system (e.g., your computer) and their network. Through this connection, your data packets travel through the ISP’s infrastructure and eventually reach the Internet backbone, enabling you to access various online services and resources.
ITM-2022
Q.1
(b) Backbone and Access Network.
Q.2
Answer the following in brief:
(a) How are Internet addresses organized?
(b) What are the various modes of connecting to the By Internet?
(c) How is the purpose of DNS in the Internet?
Q.3
Answer the following questions in the context of World Wide Web:
(a) What is a Web browser? Name some popular Web browsers.
(b) How does a search engine work?
(c) What is the role of HTTP and FTP?
Q.4
(a) Sketch the TCP/IP model and give a brief description of its core protocols.
Q.5
Q.6
Q.7
Answer the following questions in brief:
(a) Give an introduction of Web Servers and name some popular web servers.
(b) Describe the access and usage of any one of the web servers.
(c) What is the purpose of Intrusion detection system?
Q.8
(a) Describe the threats and attacks to which the Internet may be vulnerable.