Understanding the Internet: Core Concepts and Technologies

Understanding the Internet: A Global Network

The Internet is a global network of interconnected computers that any device can join. It functions as a Wide Area Network (WAN), which is essentially a series of connected Local Area Networks (LANs).

Data packets are transmitted between computers using protocols that govern how information is sent and received.

Key Internet Technologies and Services

Technologies and services available over the Internet include:

• Web Pages: HTML documents presenting images, sound, and text, accessed via a web browser.
• Web Applications: Software accessed through a web browser.
• Native Applications: Applications developed for specific devices (e.g., smartphones), accessible without a browser.
• Email: Electronic mail communication.
• File Sharing: Exchanging digital files between users.
• Voice Calls: Real-time audio communication over the Internet.
• Streaming Media: Delivering audio and video content in real-time.

Web Browsers: Your Gateway to the Internet

A web browser is software that allows users to access web pages and web applications on the Internet. Many browsers are available, typically free to download and install.

The Internet of Things (IoT) Explained

The Internet of Things (IoT) refers to the concept of networking numerous physical devices, enabling them to collect and transmit data.

Broadband Internet Connections

Internet connectivity is established through both physical wires and wireless connections. Broadband internet, for instance, is primarily transmitted via physical wires laid underground and beneath oceans.

• Examples: ADSL, 3G, Cable, Fiber Optic.

Internet Protocols: The Rules of the Web

The Internet operates much like a road network, adhering to specific rules known as protocols. Just as a road has a limited capacity for vehicles (data), the Internet has bandwidth limitations. Excessive traffic can lead to congestion, resulting in reduced bandwidth and slower performance.

When two devices initiate communication, they perform a process called handshaking. During this, the client requests access, the server grants it, and the necessary protocols are established. Once handshaking is complete, data transfer can commence.

Protocols dictate how computers send and receive messages. Data packets travel from a source to a destination, hopping between routers. This method of exchanging data packets is known as packet switching.

TCP/IP: The Internet Protocol Suite

TCP/IP (Transmission Control Protocol/Internet Protocol), also known as the Internet Protocol Suite, is the fundamental set of protocols used across the Internet. It organizes how data packets are communicated, ensuring they contain essential information such as:

• Source and destination IP addresses
• Port numbers
• Sequence numbers for reassembly
• Checksums for error detection

Web Addresses: URLs and IP Addresses

Every website address has a Uniform Resource Locator (URL) with an equivalent IP address. A web address typically contains the following components, from left to right:

• Protocol: e.g., http:// or https://
• Subdomain: e.g., www.
• Domain Name: e.g., example
• Top-Level Domain (TLD): e.g., .com, .org, .net
• Path/Resource: e.g., /pages/about.html