4.3.1 What is the Internet?
The internet is a vast global network that connects millions of computers and devices worldwide, enabling communication, data exchange, and access to online services. Unlike a single network that operates within a defined area, the internet is a network of networks, meaning it interconnects smaller private and public networks, allowing them to communicate using standardized protocols.
The internet is not owned or controlled by a single entity. Instead, it operates through a decentralized system of interconnected computers, servers, and networks maintained by various organizations, businesses, and government agencies. It uses a combination of physical infrastructure, such as fiber-optic cables, satellites, and wireless networks, along with communication protocols that dictate how data travels between devices.
Functions of the Internet
The internet supports a wide range of functions that have become essential to modern life, including:
- Communication – Sending emails, making video calls, messaging via instant chat applications.
- Information Access – Searching for information, accessing online databases, reading digital articles.
- Entertainment – Streaming music and videos, playing online games, watching live broadcasts.
- E-Commerce – Online shopping, digital payments, banking transactions.
- Cloud Computing – Storing files and running software applications remotely.
- Social Networking – Engaging with others through platforms like social media and forums.
The internet enables real-time communication and access to global resources, making it one of the most significant technological advancements in human history.
4.3.2 The Role of Internet Service Providers (ISPs)
An Internet Service Provider (ISP) is a company that provides individuals, businesses, and institutions with access to the internet. ISPs act as the intermediaries between end-users and the global internet infrastructure, ensuring that data packets travel efficiently between devices.
How ISPs Work
ISPs operate vast networks of servers, routers, and physical transmission lines, such as fiber optics and undersea cables, to facilitate internet connectivity. They are responsible for:
- Assigning IP addresses to users so that devices can be uniquely identified on the internet.
- Managing bandwidth and speed based on the user’s internet plan.
- Routing data packets across various networks to deliver requested content.
- Implementing security measures such as firewalls and encryption to protect users.
Types of ISPs
There are different categories of ISPs based on the services they provide:
- Broadband ISPs – Offer high-speed internet access through fiber-optic, DSL, or cable connections.
- Mobile Network ISPs – Provide internet access using mobile data via 4G and 5G networks.
- Satellite ISPs – Enable internet connectivity in remote areas using communication satellites.
- Wireless ISPs – Deliver internet via radio signals, commonly used in rural and developing regions.
Examples of ISPs
In Malaysia, several ISPs provide internet services:
- TM Unifi – The largest fiber broadband provider, offering high-speed internet.
- Maxis Fibre – A well-known provider of fiber-optic internet for home and business users.
- CelcomDigi – A major mobile and wireless broadband provider.
- TIME Internet – A high-speed fiber network provider focused on urban areas.
Globally, some well-known ISPs include:
- AT&T (United States)
- Vodafone (United Kingdom, Europe)
- Starlink (Satellite internet by SpaceX)
ISPs play a crucial role in connecting homes, businesses, and governments to the broader internet infrastructure.
4.3.3 How Websites Are Delivered
When a user types a web address (URL) into their browser, a series of complex operations occur within seconds to retrieve and display the webpage. The process involves multiple steps and relies on different technologies and protocols.
Step-by-Step Process of Accessing a Website
- User Requests a Web Page:
- The user enters a URL (e.g., www.wikipedia.org) in their browser.
- DNS Resolution:
- The browser contacts the Domain Name System (DNS) to convert the human-readable domain name into a numerical IP address.
- Example: www.wikipedia.org → 198.35.26.96.
- Connection to the Web Server:
- The browser sends a request to the IP address of the website’s server using the Hypertext Transfer Protocol (HTTP) or its secure version HTTPS.
- Data Transmission in Packets:
- The web server processes the request and sends the website’s data in small units called packets through the internet.
- These packets travel through multiple network routers to reach the user’s device.
- Page Rendering in the Browser:
- The browser reassembles the packets and displays the web page, loading images, text, and interactive elements accordingly.
This entire process happens almost instantly due to the efficiency of modern networking technologies.
4.3.4 Key Internet Concepts
IP Address (Internet Protocol Address)
An IP address is a unique identifier assigned to every device connected to the internet. It acts like a digital postal address, allowing computers and websites to send and receive information accurately.
There are two main types of IP addresses:
- IPv4 (Internet Protocol version 4) – Uses a 32-bit numerical format (e.g., 192.168.1.1).
- IPv6 (Internet Protocol version 6) – Uses a 128-bit hexadecimal format, allowing more unique addresses (e.g., 2001:db8:85a3::8a2e:370:7334).
IPv6 was introduced due to the increasing number of internet-connected devices, as IPv4 addresses were running out.
Domain Name System (DNS)
The Domain Name System (DNS) is a system that translates website names into IP addresses. This allows users to access websites using human-friendly names instead of remembering long numerical addresses.
For example:
- Instead of typing 172.217.160.78, a user can simply type www.google.com.
- The DNS automatically resolves www.google.com to its corresponding IP address and directs the browser to the correct server.
Web Servers and Hosting
A web server is a specialized computer that stores website files and delivers them to users when requested. Websites are hosted on these servers, which can be:
- Shared Hosting – Multiple websites share the same server.
- Dedicated Hosting – A single website has full control over a server.
- Cloud Hosting – Websites are distributed across multiple virtual servers for reliability.
Web servers are critical for storing, managing, and serving websites efficiently.
4.3.5 The Physical Infrastructure of the Internet
The internet relies on a physical network infrastructure to connect devices and transfer data worldwide. Some key components include:
- Fiber Optic Cables: The backbone of high-speed internet, transmitting data using light signals.
- Undersea Cables: Submarine fiber optic cables laid on the ocean floor that connect continents.
- Satellites: Provide wireless internet access in remote and rural areas.
- Cell Towers and Wireless Networks: Support mobile internet access via 4G and 5G networks.
- Routers and Switches: Direct data packets through networks, ensuring they reach the correct destination.
Without this vast physical infrastructure, internet communication would not be possible.
4.3.6 Summary of Key Concepts
- The internet is a global network of interconnected computers that enables worldwide communication and information exchange.
- Internet Service Providers (ISPs) act as intermediaries, granting users access to the internet through various technologies.
- Websites are accessed through DNS resolution, which translates domain names into IP addresses.
- Web servers store and manage website data, allowing users to retrieve web pages through HTTP/HTTPS protocols.
- The internet relies on a physical infrastructure of fiber-optic cables, undersea connections, satellites, and wireless networks.
Understanding internet infrastructure helps students grasp how digital communication works and how data is transferred efficiently across the globe.
Next Chapter Preview
In the next section, 4.4 Data Transmission and Packets, we will explore how information is broken into packets, transmitted over networks, and reassembled at the destination. This will build upon the concepts introduced here and further explain how data moves securely and efficiently across the internet.