Computer Study Notes: Cybersecurity

Definition: Practices, technologies, and processes designed to protect digital information and systems from unauthorized access, use, disclosure, disruption, modification, or destruction.
Threats:
- Malware (viruses, worms, Trojan horses)
- Phishing
- Ransomware
- SQL injection
- Cross-site scripting (XSS)
Security measures:
- Firewalls
- Encryption
- Access control (passwords, biometrics)
- Regular software updates and patches
- Backup and recovery systems

Definition: Development of computer systems that can perform tasks that typically require human intelligence, such as:
- Learning
- Problem-solving
- Reasoning
- Perception
AI applications:
- Natural Language Processing (NLP)
- Computer Vision
- Robotics
- Expert Systems
- Game Playing (e.g., chess, Go)
AI types:
- Narrow or Weak AI (task-specific)
- General or Strong AI (human-like intelligence)
- Superintelligence (significantly surpassing human intelligence)

Definition: Connection of devices to exchange data, resources, and services.
Network types:
- Local Area Network (LAN)
- Wide Area Network (WAN)
- Wireless Network (WLAN)
- Metropolitan Area Network (MAN)
- Internet
Network protocols:
- TCP/IP (Transmission Control Protocol/Internet Protocol)
- HTTP (Hypertext Transfer Protocol)
- FTP (File Transfer Protocol)
- DNS (Domain Name System)

Definition: Programs and operating systems that manage computer hardware components and provide services to users.
Software types:
- Operating System (OS)
- Application software (productivity, games, utilities)
- Programming languages (e.g., Python, Java, C++)
- Firmware (embedded software)
Software development:
- Design
- Implementation
- Testing
- Deployment
- Maintenance

Cybersecurity is a set of practices, technologies, and processes designed to protect digital information and systems from unauthorized access, use, disclosure, disruption, modification, or destruction.
Common threats to cybersecurity include:
- Malware (viruses, worms, Trojan horses) that compromise system integrity
- Phishing attacks that deceive users into divulging sensitive information
- Ransomware that encrypts data and demands payment for decryption
- SQL injection attacks that exploit database vulnerabilities
- Cross-site scripting (XSS) attacks that inject malicious scripts into websites
To mitigate these threats, various security measures can be employed, including:
- Firewalls that block unauthorized access to networks
- Encryption that protects data in transit and at rest
- Access control mechanisms, such as passwords and biometrics, that authenticate user identities
- Regular software updates and patches that fix vulnerabilities and improve system resilience
- Backup and recovery systems that ensure business continuity in the event of data loss or system failure

Artificial Intelligence (AI) is a field of study focused on developing computer systems that can perform tasks that typically require human intelligence, such as:
- Learning from data and experiences
- Problem-solving and decision-making
- Reasoning and inference
- Perception and understanding of the environment
AI has numerous applications, including:
- Natural Language Processing (NLP) that enables computers to understand and generate human language
- Computer Vision that enables computers to interpret and understand visual data from images and videos
- Robotics that enables robots to perform tasks that typically require human intelligence
- Expert Systems that mimic human expertise in specific domains
- Game Playing that enables computers to compete with humans in complex games like chess and Go
There are several types of AI, including:
- Narrow or Weak AI that is designed to perform a specific task
- General or Strong AI that has human-like intelligence and can perform any intellectual task
- Superintelligence that significantly surpasses human intelligence

A computer network is a connection of devices that communicate with each other to exchange data, resources, and services.
There are several types of networks, including:
- Local Area Network (LAN) that connects devices in a limited geographical area
- Wide Area Network (WAN) that connects devices over a larger geographical area
- Wireless Network (WLAN) that connects devices wirelessly
- Metropolitan Area Network (MAN) that connects devices in a metropolitan area
- Internet that connects devices worldwide
Networks use various protocols to communicate, including:
- TCP/IP (Transmission Control Protocol/Internet Protocol) that provides a common language for devices to communicate
- HTTP (Hypertext Transfer Protocol) that enables communication between web browsers and servers
- FTP (File Transfer Protocol) that enables file transfer between devices
- DNS (Domain Name System) that translates domain names to IP addresses

Computer software refers to the programs and operating systems that manage computer hardware components and provide services to users.
There are several types of software, including:
- Operating System (OS) that manages hardware components and provides a platform for running applications
- Application software (productivity, games, utilities) that performs specific tasks
- Programming languages (e.g., Python, Java, C++) that enable software development
- Firmware (embedded software) that is embedded in hardware devices
The software development life cycle includes:
- Design that involves planning and specifying software requirements
- Implementation that involves writing code and testing software
- Testing that involves verifying software functionality and performance
- Deployment that involves releasing software to users
- Maintenance that involves updating and fixing software issues