Introduction to Computing

Introduction to Computing

Session Overview

• Lecturer: Elias Kalenga
• Institution: NorthRise University
• Session Focus: The Internet, the Web, and Electronic Commerce

Devotion

Text Overview

• Source: Romans 8:29

Devotion Focus: Divine Interruptions

• Story of Sara, who prioritized helping a struggling family despite her busy schedule.
• Learning to defer to God's plans can lead to personal joy and blessings in serving others.
• Example cited from 2 Kings 4:8 about a woman's hospitality towards Elisha and its rewards.

Course Objectives

1. Describe a network.
2. Explain the benefits of a network.
3. Describe the types of networks.
4. Explain advantages and disadvantages of networked computing.
5. Describe communication media.
6. Describe communications hardware and software, and network architecture.
7. Explain the origin of the Internet, how to connect, and how it works, including major features of the Internet and their functions.
8. Demonstrate troubleshooting methods for web page issues.

The Internet and the Web

Overview

• Definition of the Internet: A global network of interconnected computers for data exchange and communication.
• Services Enabled by the Internet:
  • Email
  • File Sharing
  • Real-time Messaging
• World Wide Web (Web):
  • Part of the Internet composed of interconnected websites and applications accessed through browsers.
  • Revolutionized information sharing utilizing technologies like HTML (Hypertext Markup Language), HTTP (Hypertext Transfer Protocol), and URLs (Uniform Resource Locators).
• Electronic Commerce (E-commerce):
  • Involves buying and selling goods/services online.
  • Platforms include Amazon and Alibaba, enabling faster and accessible transactions.
• Impact: Together, these elements have reshaped communication, business, and daily life, fueling the digital economy.

Objective 1: Describe a Network

Definition

• Network: A collection of two or more computers connected to each other.

Introduction to Networks

• Networking facilitates communication essential in modern society.
• Users connect to networks either quickly or automatically, allowing for instant data access.

Network Fundamentals

• Computers: Individual devices forming the network.
• Connections: Links enabling communication among devices.

Types of Networks

Overview

1. Local Area Network (LAN): Confined to limited geographical areas.
2. Wide Area Network (WAN): Connects multiple LANs across larger geographical areas.
3. Data Communications: Transmission of data from one location to another, with the Internet being the largest network globally.
4. Communication Channels: The paths through which data is transmitted, which can be either physical or wireless.
5. Transmission Media:
   • Physical Media: Includes twisted-pair cable, coaxial cable, and fiber-optic cable.
   • Wireless Media: Utilizes radio signals, microwaves, and satellite transmission.
6. Network Components: Most networks comprise a server and client devices, including modems for communication.

Objective 2: Explain the Benefits of a Network

Advantages of Networking

• Enhanced Communication: Changed interactions through various electronic platforms.
• Information Sharing: Access to data and resources across global networks.
• Searching & Researching: Easier access to vast information, replacing traditional library visits.
• E-commerce: Online business activities made viable and efficient through networks.
• Online Training: Flexible and convenient learning opportunities.
• Telecommuting: Facilitates remote working arrangements.
• Collaborative Environment: Enables seamless teamwork and project collaboration.
• Hardware & Software Sharing: Centralizes resource access, reducing overall costs.
• Entertainment: Provides access to diversified gaming and media options across networks.

Objective 3: Describe Types of Networks

Classification

1. Local Area Network (LAN): Allows devices in a limited area to connect and communicate.
2. Wireless Local Area Network (WLAN): Operates without physical cabling, connecting devices wirelessly.
3. Wide Area Network (WAN): Spans large geographical areas by connecting multiple LANs.
4. Peer-to-Peer (P2P): Equal connection among all computers with no designated server.
5. Intranet: A private network used within an organization.
6. Extranet: An intranet that allows access to specific external users.
7. Internet: A global network connecting billions of devices.

Objective 4: Explain Advantages and Disadvantages of Networked Computing

Advantages

1. Resource Sharing: Reduces individual hardware needs.
2. Improved Communication: Fast communication methods enhanced by electronic means.
3. Centralized Data Management: Ensures data is consistent and accessible by multiple users.
4. Cost Efficiency: Lowers expenses through shared resources.
5. Scalability: Adaptability of networks with increasing demands.
6. Remote Access: Allows access from various locations.
7. Collaboration: Promotes real-time teamwork.

Disadvantages

1. Security Risks: Vulnerable to cyber threats.
2. Dependence on Network Stability: Disruptions can affect productivity.
3. High Setup & Maintenance Costs: Initial and ongoing expenses can be significant.
4. Privacy Concerns: Sensitive data may be exposed.
5. Complexity: Large networks need specialized management.
6. Bandwidth Limitations: Heavy traffic can slow down performance.
7. Risk of Data Loss: Potential loss if backups are not properly maintained.

Objective 5: Describe Communication Media

Overview

• Communication Media: Various channels for data, voice, and video transmission.
• Categories:
  • Guided (Wired): Physical connections, i.e., cables.
  • Unguided (Wireless): Transmits data through electromagnetic waves.

Wired Communication Media

1. Twisted Pair Cables: Common in LANs; categorized into UTP (Unshielded) and STP (Shielded).
2. Coaxial Cables: Used for TV and internet, offering better shielding.
3. Fiber Optic Cables: High-speed data transmission with minimal loss.

Wireless Communication Media

1. Radio Waves: Long-distance communication for Wi-Fi and mobile networks.
2. Microwaves: Point-to-point communication, requires line-of-sight.
3. Infrared: Short-range devices such as remote controls.
4. Satellite: Global communication even in remote areas, but with high latency.

Objective 6: Describe Communications Hardware and Software, and Network Architecture

Communications Hardware

• Transmitters: Devices that send data.
• Receivers: Devices that receive data.
• Processers: Devices processing transmitted data.

Key Examples

• Modem: Converts signals for transmission.
• Router: Connects networks and directs data.
• Switch: Forwards data within LANs.
• Network Interface Card: Connects computers to networks.
• Access Point: Connects wireless devices to wired networks.
• Firewall: Filters network traffic for security.

Communications Software

• Network Operating Systems: Manage resource sharing.
• Protocol Suites: Define data transmission rules (e.g., TCP/IP).
• Management Software: Monitors network performance (e.g., Wireshark).
• Applications: Examples include email clients and web browsers.

Network Architecture

Types:

1. Peer-to-Peer (P2P): Equal status for all devices, suitable for small networks.
2. Client-Server: Centralized management with servers handling resources.
3. Network Topologies: Includes bus, star, ring, mesh, and hybrid layouts, each with unique advantages and disadvantages.

Objective 7: Explain the Origin of the Internet

Historical Context

• Origin in the late 1960s as ARPANET by the U.S. Department of Defense.

Key Milestones

• 1969: First message sent (UCLA to Stanford).
• 1970s-1980s: Development of TCP/IP.
• 1989: Tim Berners-Lee invented the WWW.
• 1990s: Internet commercialization began.
• 2000s-Present: Growth of broadband, cloud computing, and IoT.

How to Connect to the Internet

• Necessary Components:
  • Hardware: Computer, modem, router.
  • ISP: (e.g., Comcast, AT&T).
  • Software: Web browsers and communication protocols like TCP/IP.

How the Internet Works

Process Overview

• Sending requests and data packets through standardized protocols.

Data Transmission Steps:

1. Device sends a request.
2. Request travels through the ISP to a DNS server for IP address resolution.
3. Data is transmitted in packets across networks.
4. Destination server processes and returns the data.
5. Device reassembles packets for display.

Key Features and Functions of the Internet

Objective 8: Demonstrate Web Browsing Troubleshooting

Basic Troubleshooting Steps

1. Check Your Internet Connection:
   • Use another site or app to confirm connectivity.
   • Restart router/modem if necessary.
2. Refresh the Page:
   • Press F5 (Windows) or Cmd + R (Mac).
3. Check the URL:
   • Verify the website address entered.
4. Try a Different Browser:
   • Test in alternative browsers if issues persist.

Browser-Specific Issues

• Clear cache and cookies regularly to maintain browser performance.
• Disable extensions temporarily to test for conflicts.
• Reset browser settings if misconfigurations are suspected.

Website-Specific Issues

• Use Down Detector for global outage checks.
• VPN/Proxy setups can bypass regional restrictions.
• Contact website support if problems with specific sites arise.

Common Client-Side Errors

Quick Troubleshooting Guide

• Refresh page, check connection, clear cache, try another browser, restart router, check site status, contact admin if issues persist.