Internet and Mobile Computing

Introduction to the Internet

The Internet is a global network that connects millions of computers worldwide. Think of it as a massive highway system that allows information to travel between devices across the globe. The Internet wasn’t built by a single organization—it evolved over time as networks connected to other networks.

How the Internet Works

Packet Switching

When you send information over the Internet, it doesn’t travel as one big chunk. Instead, it’s broken down into small packets. Each packet contains:

• The data itself
• The sender’s address
• The destination address
• Instructions for reassembly

These packets may take different routes to reach the destination, where they’re reassembled into the original message. This method makes the Internet very reliable—if one path is blocked, packets can find another way.

IP Addresses

Every device connected to the Internet needs a unique identifier called an IP (Internet Protocol) address. It looks something like 192.168.1.1. Think of an IP address as your home address—it tells the Internet where to deliver information.

Domain Name System (DNS)

While computers understand IP addresses, humans find it easier to remember names. The Domain Name System works like a phone book, translating human-friendly website names (like www.kerala.gov.in) into the numerical IP addresses computers need.

Internet Protocols

For computers to communicate, they need to speak the same language. Internet protocols are sets of rules that define how data is formatted, transmitted, and received. The most important collection of protocols is TCP/IP (Transmission Control Protocol/Internet Protocol), which forms the foundation of Internet communication.

Common Internet Services

World Wide Web (WWW)

The Web is a system of interlinked documents accessible via the Internet. It’s just one service that runs on the Internet, though many people think they’re the same thing. To access the Web, you use a browser like Chrome, Firefox, or Edge.

Email

Electronic mail allows users to send messages and attachments regardless of distance. Email addresses have two parts separated by @ (example: student@school.edu) – the username and the domain name.

File Transfer Protocol (FTP)

FTP is used for transferring files between computers on a network. It’s particularly useful for downloading or uploading large files to websites or servers.

Voice Over IP (VoIP)

VoIP converts your voice into digital signals that travel over the Internet, allowing you to make calls using an Internet connection instead of a regular phone line. Services like WhatsApp calls and Skype use VoIP technology.

Social Media

Platforms like Facebook, Instagram, and Twitter use the Internet to connect people, enabling them to share content and communicate instantly across the world.

Internet Connection Types

Dial-up Connection

This older technology uses telephone lines and modems to connect to the Internet. It’s very slow (up to 56 Kbps) and blocks the phone line when in use.

Broadband Connections

These high-speed connections include:

• DSL (Digital Subscriber Line): Uses existing telephone lines but doesn’t block phone calls
• Cable: Provided by TV cable companies, offering faster speeds than DSL
• Fiber Optic: Uses light signals through thin glass fibers, providing the fastest speeds
• Satellite: Beams Internet data from space, useful in remote areas with no cable or DSL

Wireless Connections

• Wi-Fi: Creates wireless networks in homes, schools, and public places
• Mobile Data: 3G, 4G, and 5G networks provide Internet access through cellular towers

Web Browsers and Search Engines

Web Browsers

Browsers are applications that retrieve and display web pages. Popular browsers include Chrome, Firefox, Safari, and Edge. They interpret HTML, CSS, and JavaScript to render websites properly.

Search Engines

Search engines help users find information on the vast Internet. Google, Bing, and Yahoo use complex algorithms to index billions of web pages and return relevant results for search queries.

Internet Security

Threats

• Viruses: Programs that can replicate and damage your computer
• Malware: Malicious software designed to harm or exploit devices
• Phishing: Attempts to trick users into revealing personal information
• Hacking: Unauthorized access to computer systems

Protection Measures

• Firewalls: Monitor and filter network traffic
• Antivirus Software: Detects and removes malicious programs
• Strong Passwords: Combination of letters, numbers, and symbols
• Two-Factor Authentication: Adds an extra layer of security beyond passwords
• Regular Updates: Keeps software patched against known vulnerabilities

Internet of Things (IoT)

IoT refers to everyday objects embedded with sensors, software, and connectivity that allow them to connect and exchange data. Examples include:

• Smart refrigerators that track food items
• Connected thermostats that learn your schedule
• Wearable fitness devices that monitor health metrics
• Smart speakers that respond to voice commands

Mobile Computing

What is Mobile Computing?

Mobile computing refers to technology that allows transmission of data via a computer without having to be connected to a fixed physical link. The main concept involves:

• Portable hardware (mobile devices)
• Mobile software
• Communication networks

Mobile Devices

Smartphones

Modern smartphones are powerful computers that fit in your pocket. They feature:

• Touchscreens
• Cameras
• Various sensors (GPS, accelerometer, etc.)
• Powerful processors
• Multiple connectivity options

Tablets

Tablets offer larger screens than smartphones while remaining portable. They’re ideal for consuming media, reading, and light productivity tasks.

Laptops

While less portable than smartphones and tablets, laptops provide more computing power and better input options through physical keyboards.

Wearable Devices

Smartwatches, fitness trackers, and other wearables represent the newest category of mobile devices, designed to be worn on the body.

Mobile Operating Systems

Android

Developed by Google, Android is an open-source operating system used by manufacturers like Samsung, Xiaomi, OnePlus, and many others. It offers high customizability and runs on a wide range of devices.

iOS

Apple’s iOS powers iPhones and iPads. It’s known for its security, smooth performance, and tightly controlled ecosystem.

Mobile Applications (Apps)

Mobile apps are software programs designed specifically for mobile devices. They fall into several categories:

• Native Apps: Built specifically for one platform using platform-specific programming languages
• Web Apps: Run in browsers but designed for mobile screens
• Hybrid Apps: Combine features of both native and web apps

Apps are distributed through app stores like Google Play Store and Apple App Store, which review apps for quality and security.

Mobile Networks and Connectivity

Cellular Networks

• 3G: Third-generation networks that introduced mobile internet
• 4G/LTE: Fourth-generation networks offering faster speeds, enabling video streaming and complex apps
• 5G: The newest generation promising dramatically faster speeds, lower latency, and connecting many more devices

Wi-Fi

Mobile devices connect to wireless local area networks (WLANs) for faster, more stable internet access when available.

Bluetooth

Short-range wireless technology for connecting devices like headphones, speakers, and other peripherals.

NFC (Near Field Communication)

Allows devices to communicate when held very close together, enabling contactless payments and quick pairing.

Cloud Computing and Mobile

Cloud computing extends mobile capabilities by:

• Storing data remotely instead of on the device
• Performing resource-intensive processing on remote servers
• Synchronizing information across multiple devices
• Providing backup and recovery options

Mobile Computing Challenges

Security and Privacy

Mobile devices contain sensitive personal information and are vulnerable to loss, theft, and hacking. Security measures include:

• Biometric authentication (fingerprint, face recognition)
• Encryption
• Remote wiping capabilities

Battery Life

Despite advances, battery technology remains a limitation for mobile devices, especially as apps grow more power-hungry.

Connectivity Issues

Mobile connectivity can be inconsistent depending on location, weather, and network congestion.

Impact of Internet and Mobile Computing

The combination of the Internet and mobile computing has transformed society in numerous ways:

• Education: Access to vast information resources from anywhere
• Business: E-commerce, remote work, and new business models
• Healthcare: Telemedicine and health monitoring
• Communication: Instant messaging and video calls across continents
• Entertainment: Streaming services, mobile gaming, and social media
• Government: Online public services and increased transparency

Understanding these technologies helps you navigate our increasingly connected world and prepares you for future technological developments.

Complete Chapter-wise Hsslive Plus One Computer Science Notes

Our HSSLive Plus One Computer Science Notes cover all chapters with key focus areas to help you organize your study effectively:

• Chapter 1 The Discipline of Computing
• Chapter 2 Data Representation and Boolean Algebra
• Chapter 3 Components of the Computer System
• Chapter 4 Principles of Programming and Problem Solving
• Chapter 5 Introduction to C++ Programming
• Chapter 6 Data Types and Operators
• Chapter 7 Control Statements
• Chapter 8 Arrays
• Chapter 9 String Handling and I/O Functions
• Chapter 10 Functions
• Chapter 11 Computer Networks
• Chapter 12 Internet and Mobile Computing