Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

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Performance objectives

• Evaluate system and network performance using monitoring tools.
• Implement basic security measures against common threats.
• Design a backup and recovery plan.
• Explain the importance of software updates.
• Describe common malware and social engineering attacks.

Lesson summary

This week, we delve into the critical area of system and network performance, security, and backups. In today's interconnected world, whether you're using online banking, accessing educational resources, or simply connecting with friends and family, the performance, security, and availability of the underlying systems are paramount. Poor performance can lead to frustration and lost productivity, while security breaches can compromise your personal information. Effective backups are crucial for data recovery in case of hardware failure, cyberattacks, or even accidental deletion.

Lesson notes

2.1 System Performance: System performance refers to how efficiently a computer system executes tasks. Several factors affect performance, including: CPU (Central Processing Unit): The "brain" of the computer. A faster CPU generally means better performance. Its performance is often measured in clock speed (GHz) and number of cores.

RAM (Random Access Memory): Temporary storage for data that the CPU is actively using. Insufficient RAM leads to slow performance as the system relies on the slower hard drive for virtual memory. Common RAM sizes include 8GB, 16GB and 32G

B. Storage (Hard Drive or SSD): Where data is stored. SSDs (Solid State Drives) are significantly faster than traditional HDDs (Hard Disk Drives), leading to faster boot times and application loading.

Graphics Card (GPU): Important for graphics-intensive tasks like gaming, video editing, and CAD (Computer-Aided Design).

Operating System (OS): A well-optimized OS ensures efficient resource allocation.

Network Connectivity: A slow network connection limits access to online resources and can significantly impact performance.

Monitoring Tools: Windows Task Manager, Resource Monitor (Windows), and Activity Monitor (macOS) are built-in tools to monitor CPU usage, memory usage, disk activity, and network activity. Third-party tools like CCleaner can also help identify performance issues and clean up unnecessary files.

Example: A student complains their laptop is running slowly. Using Task Manager, they notice the CPU usage is consistently at 100% when running multiple applications. Further investigation reveals that the laptop only has 4GB of RAM, which is insufficient for the number of applications being used simultaneously. The solution is to close unnecessary applications or upgrade the RAM to 8GB or 16GB. 2.2 Network Performance: Network performance refers to the efficiency and speed with which data is transmitted across a network.

Key factors include: Bandwidth: The amount of data that can be transmitted per unit of time, usually measured in bits per second (bps) or megabits per second (Mbps).

Latency: The delay in data transfer, measured in milliseconds (ms). High latency can result in slow response times.

Packet Loss: When data packets are lost during transmission, they need to be retransmitted, slowing down the network.

Network Congestion: Occurs when the network is overloaded with traffic, leading to slower speeds and increased latency.

Network Infrastructure: The quality of network cables, routers, and switches impacts performance.

Monitoring Tools: Ping (measures latency), Traceroute (maps the route data takes and identifies bottlenecks), and network speed test websites (e.g., speedtest.net).

Example: A small business in a rural area experiences slow internet speeds. Using a speed test website, they determine their download speed is significantly lower than the advertised speed from their ISP (Internet Service Provider). Further investigation reveals that the ISP is experiencing congestion during peak hours. The business could explore upgrading to a faster internet plan or switching to a different ISP if available. 2.3 Security: Security measures protect computer systems and networks from unauthorized access, data breaches, and malware.

Common security threats include: Malware: Malicious software, including viruses, worms, Trojans, ransomware, and spyware.

Phishing: Attempts to trick users into revealing sensitive information (passwords, credit card details) through deceptive emails or websites. Often uses fake links or appears to be from a legitimate organization. Be wary of emails asking for personal information, especially those with a sense of urgency.

Social Engineering: Manipulating people into divulging confidential information.

Hacking: Unauthorized access to computer systems or networks.

Denial-of-Service (DoS)

Attacks: Overwhelming a system with traffic, making it unavailable to legitimate users.

Security Measures: Antivirus Software: Detects and removes malware. Popular options include Avast, AVG, and Kaspersky.

Firewall: Blocks unauthorized access to a network or computer. Windows Firewall is a built-in option.

Strong Passwords: Use a combination of uppercase and lowercase letters, numbers, and symbols. Avoid using personal information.

Two-Factor Authentication (2FA): Adds an extra layer of security by requiring a second verification code (e.g., from a mobile app) in addition to a password.

Software Updates: Regularly update the operating system and applications to patch security vulnerabilities.

User Awareness: Educate users about phishing attacks and social engineering tactics.

Example: An employee receives an email seemingly from their bank asking them to update their account details. The email contains a link to a fake website that looks identical to the bank's website. If the employee clicks the link and enters their login credentials, the attacker can steal their information.