Operating Systems and Audio Technology Quiz

Information Technology (IEB) Exam Prep

• This document is a compilation of various sources' definitions and explanations to assist in IT preparation. No claim is made to its originality or intellectual property.
• It adheres to the IEB's SAGS document (Appendix G) as of 2022.

System Technologies

Hardware and Software

• Hardware is the physical components of a computer, including CPU and RAM
• Software is a set of computer programs and associated documentation and data, or a set of instructions that tell a computer what to do (e.g., Microsoft Word)
• ICT systems use electronic technologies and techniques to manage, capture, transmit, and display information and knowledge.
• Computers are devices that process data according to instructions, typically electronic.
• Input Processing Output (IPO) Model describes a system with input, processing, and output stages
  • Input involves providing data to the system
  • Processing occurs when the computer interprets and executes the input
  • Output is the result after processing.
• Advantages of Using Computers
  • Speed
  • Accuracy
  • Repetitiveness
  • Versatility
• Disadvantages of Using Computers
  • High cost
  • Takes over human jobs
  • Waste produced by computers
  • Health problems (eyes, neck, back)

Data

• Data is a collection of facts.
• Raw and unorganized, meaningless on its own
• Information is data put into context.
  • Organized and analyzed
  • Meaningful

System Types

• Laptops = Portable personal computers (PC)
• Desktops = PCs for regular use at a single location
• Servers = computers or programs that manage central resources or services in a network

Embedded Computers

• Hardware and software that performs a specific function (e.g., camera in a washing machine)
• Smart wear = Wearable technology for monitoring activity and condition
• Tablets = Portable touchscreen devices
• Smartphones = Portable computing devices combining mobile and telephone functions
• Single Board Computers (SBC) = Complete computers on a single circuit board (e.g., Raspberry Pi, Arduino)

Processing Power

• Processing power, from highest to lowest: server, supercomputer, desktop, mobile.

Operating Systems

• The main control program in a user's device.
• Creates a user interface.
• Loads and runs programs.
• Manages resources
• Acts as an interface between hardware and application programs (e.g., Windows, macOS, Android, iOS)

Application Software

• Stand-alone applications (e.g., Notepad, MS Word) need no other applications to run.
• Network applications (e.g., web browser) communicate with other applications on different hosts.

Main Hardware Components

• CPU: made up of the control unit (CU), arithmetic logic unit (ALU), and registers
• Primary Storage: RAM, BIOS, ROM
• Secondary Storage: HDDs, SSDs, SD cards, flash drives
• Input devices: pointing devices (mouse), keyboards, scanners, microphones, biometric devices
• Output devices: monitors, printers, speakers
• Ports: USB, HDMI
• Motherboard: connects components and devices

CPU Design

• Registers
  • Stores current instructions and data
  • Instructions are broken down and individually stored in segments
• Control Unit (CU): Controls the execution of instructions, sends read/write signals to memory
• Arithmetic Logic Unit (ALU): Performs calculations and logical comparisons. Data loaded from RAM is processed and saved.

Serial Processing

• Outdated; one instruction at a time
• Single-core processors process one set of instructions sequentially

Parallel Processing

• Simultaneous execution of instructions; using multiple microprocessors

Hyperthreading

• Developed by Intel in 2002
• Thread = part of a program, a set of instructions
• Process = regards the entire program
• Hyperthreaded CPUs appear as two logical CPUs in the OS but have only one physical CPU
• Enables simultaneous execution
• Preloading next instructions into registers while processing the first one

Multiprocessing

• Multiple cores on a CPU chip.
• Entire core is duplicated instead of only the registers.
• Cache stores data for faster requests.

Processor Cache

• Faster memory close to the CPU.
• Caches instructions for faster retrieval.

Cache Hit/Miss

• Cache hit: requested data is found in the cache
• Cache miss: requested data is not found in the cache.

RAM (Random Access Memory)

• Most common: DDR SDRAM
• Double Data Rate (data transferred at the rise and fall of pulses).
• Faster than previous RAM versions.

Motherboard

• Connects components and devices.
• Uses buses, slots and ports for connections.
• Uses the system clock for timing and synchronization of all computer functions.
• Speed measured in MHz.

Internal Buses

• Transfer instructions between CPU and RAM
• Wider buses mean higher throughput
• Consist of Data Bus, Address Bus and Control Bus

External Buses

• Connect external devices to the computer for storage (e.g., PCIe, NVMe, USB, SATA)

SATA (Serial Advanced Technology Attachment)

• Connects mass storage, like hard drives

USB (Universal Serial Bus)

• Standardises connections for almost any peripheral

NVMe (Non-Volatile Memory Express)

• Connects SSDs directly to the motherboard to improve read/write speed.

M.2 Interface

• Designed for high-speed operations.
• Consumes less space.

Secondary Storage (HDD vs SSD)

• HDD (Hard Disk Drive): spinning disks
• SSD (Solid State Drive): no moving mechanical parts.
• SSDs run faster, are quieter, and are more resistant to shocks compared to HDDs.

Cloud Storage

• Data stored remotely on the internet.
• Cost based on bandwidth and storage space.

Other Caching

• Disk Cache: Hardware mechanism in a hard drive that stores frequently accessed data in RAM.
• Browser Cache: stores web pages on a user's hard disk for quicker future access
• Web/Proxy cache stores recently accessed web pages for faster future access.

Modular Design & Performance

• Devices can be repaired or upgraded without replacing the entire system.

Clock Manipulation

• Overclocking increases system clock speed, but may cause excess power consumption.

Expansion Cards

• Added to a motherboard to provide more functionality.

Co-processors

• Assist the CPU by taking over some of its workload.

Graphics

• Translation of digital data into images and colour
• Graphics Processing Unit (GPU) improves processing speed and resolution for image rendering.
• Uses Video RAM to improve graphics.

System Clock

• Regulates timing and synchronisation in computer functions.

Serial Processing

• Processing instructions one at a time.

Parallel Processing

• Simulataneous processing of data by different parts of the system (instructions/instructions sections).

Hyperthreading

• Developed by Intel in 2002
• Creates two logical processors to optimize performance.

Multiprocessing

• Multiple cores to increase processing of tasks.

Latency

• The time taken for RAM to respond to a request.

Latency vs. Throughput

• Latency represents the delay, while throughput is the rate at which data is transferred.

Buses

• Internal bus (connects CPU and RAM)
• External bus (connects to peripherals like hard drives).

Ports

• Physical connections for external devices (e.g., USB, HDMI, PCIe and SATA)

Internet and Communication Technologies

LANs (Local Area Networks)

• A group of devices connected in a close proximity for sharing resources.
• Uses Ethernet to connect devices in a LAN.
• Network devices: clients, servers, switches, routers.

Network Topology Diagrams

• Star: All devices connect to a central switch. If the switch fails, the network fails.
• Bus: All devices connect to a single cable. If the cable fails, the network fails.
• Tree: Combines star and bus topology.
• Ring: Devices connect in a closed loop, passing through each node. If a node fails, network fails.
• Mesh: A collection of wireless nodes with access points. All nodes are networked together.

Network Addressing Diagrams

• IP Address: Numerical label to allow computers to communicate over the internet. Can be static (assigned manually, less likely to change) or dynamic (changes over time). IPv4 uses 32-bits. IPv6 uses 128-bits.
• MAC Address: Unique hardware identifier for devices in a LAN. This never changes.
• ARP (Address Resolution Protocol): Links MAC addresses to IP addresses.
• DHCP (Dynamic Host Configuration Protocol): Assigns IP addresses to devices automatically. Makes IP addressing easier.
• DNS (Domain Name Servers): translates domain names to IP addresses (internet equivalent to a phonebook).

Internet Protocols

• HTTP (Hypertext Transfer Protocol): Standard protocol for transferring website pages over the internet.
• HTTPS (HTTP over Secure Socket Layer): Secure version of HTTP, used for secure transactions (e.g., banking).

Downloading

• FTP (File Transfer Protocol): Used for transferring files over the internet.
• WebDAV (Web Distributed Authoring and Versioning): Used for communication between client browsers and web servers.

Cloud Computing

• Data stored on a remote server, accessible via the internet.

Client-Server Model

• Data hosted on a remote server and used by clients.

P2P (Peer-to-Peer)

• Each computer acts as both a client and a server. Files are exchanged across the network.

Mobile Technologies

• Wearable Tech: Technology worn or near skin used to analyse human data, for health tracking or notification.
• HMD (Head Mounted Display): A visual display worn on the head (e.g. Oculus VR).
• Smart Clothing: Technology used in clothes for data collection.

Types of Networks

• Personal Area Network (PAN): Connects devices from a single user (e.g., tablet, smartphone).
• Local Area Network (LAN): connects devices within a local area.
• Metropolitan Area Network (MAN): connects devices in a city or metropolitan area.
• Wide Area Network (WAN): Connect devices in a large area (e.g. countries or continents).

Mobile Positioning & Services

• GPS (Global Positioning System)
• Location Based Services (LBS)

Cloud Computing

• Store, manage, and process data on remote servers on the Internet.

Cloud Storage

• Data storage in a remote location.
• Can be personal, private (company), or public (e.g., Dropbox, iCloud, Google Drive).
• Accessed via the internet.

Advantages

• Ease of access
• Reduced need for local storage

Disadvantages

• Data theft/loss if not properly secured
• Reliance on a stable internet connection

Data Misuse

• Data used for different purposes than collected.
• Without clear usage guidelines for the data.

Right to Privacy

• The right of individuals not having their communications and property searched.

Right to Access

• Public right to information held by government organisations or individuals.

Big Data

• Extremely large datasets.
• Requires special techniques for analysis.

Digital Heritage

• Preserving digital content for future generations.

### Information, Communication & Technology

Multimedia Online

• Combination of text, graphics, audio and video files for internet communication.
  • Downloading involves copying files to a local storage.
  • Streaming delivers data continuously without copying to a local storage.
• On-demand media allows users to select and watch/listen to content when they want to.
• VoIP = Voice over Internet Protocol. Data communication, transferring media using IP networks.

Compression Techniques

• Lossy compression results in some data loss but reduces file size. Used for images and audio.
  • JPEG
  • MP3
• Lossless compression maintains all original data, but might not reduce the file size as much. Used for text or documents.
  • ZIP

### Web Browsing

• Search Engines: Used to retrieve web information (e.g., Google, Bing, Yahoo)
• Surface Web: Part of the web that is indexed by search engines
• Deep Web: Content not indexed by surface web search engines (medical, legal, finance records)
• Dark Web: Hidden part of the Deep Web, with restricted access.

Anonymous Browsing Tools

• Onion Router (Tor): network that encrypts data to provide anonymous communication (e.g., for privacy).

Internet Service Technologies

• Evolution: Changes in how services connect to the internet.
  • Web 1.0 (static sites, limited user interaction, few developers)
  • Web 2 (dynamic sites, user interaction, social network, wikis, blogs)
  • Web 3 (personalization, real-time data notification, e-commerce, personalized experiences)
  • Web 4 (adaption to surroundings for user device)

Mobile Web Applications

• Web-based applications that can run using only a web browser.

### Errors, Threats & Security

• Human errors: wrong inputs, poor understanding of consequences of actions
• Data corruption: Loss of data.
  • Power failure can cause data to be lost.
  • Malware can steal or corrupt data.

Solutions

• Verification: Checks for consistency and correctness.
• Validation: Checks all the data for completeness, relevance and accuracy.
  • Presence: checks if the data item is present.
  • Range: Checks for values within bounds.
  • Uniqueness: checks if the data is already present.
  • Type: Checks if the data is of the correct format.

Security Threats

• Malicious Software: Viruses, malware, ransomware, phishing and social engineering.
• SQL Injection: malicious programs insert data into databases to get access.
• Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) Attacks: Overloading the server to cause denial to access.
• Hardware Failure: Faults/damage in hardware, like hard drives, power supplies and network cables.
• Software Failure: Software bugs can cause data corruption or system crashes.
• Data theft: Software or data being stolen from systems/users

Safeguards

• Firewalls: Monitor and control network traffic patterns to prevent malicious activity.
• Antivirus: Software programs that scan for and eliminate malware.
• Encryption: Encoding data to protect during transmission and storage.
• Backups: Creating copies of data on another medium to avoid data loss.
• UPS (Uninterruptible Power Supply): Prevent data loss due to power failure.

Social & Ethical Issues

• Economic Reasons: Use of computers to save costs, increase efficiency and accuracy
• Digital Divide: Unequal access to ICT resources among different demographics and regions.
• Ergonomics & Health: Use of technology can cause repetitive strain injury (RSI), eye strain, carpal tunnel syndrome.
• Privacy: Collecting, sharing and misuse of data.
• Political Effects: Using the internet for campaigning and influencing voters.
• Environmental Effects: The impact of technology on the environment (electricity use and e-waste)

### Data & Information Management

Database Management System (DBMS)

• Software for managing data in a database, including permissions, backups, and control of access.

Data Integrity Management

• Accuracy: Checks to ensure that the stored data conforms to its true value.
• Currency (Timeliness): Ensures that the data is current, up to date.
• Correctness: conformity to standards.
• Completeness: that it meets all the requirements

Data Warehousing

• Stores data from multiple sources for analysis and reporting.
• Data transformed from transactional systems for summaries or reports.
• Data stored in a normalized schema.

Data Types

• Structured Data: Data that has a predefined structure, such as numerical, textual, dates and times, which can be easily searched and understood.
• Unstructured Data: Data without a predefined structure, like images, audio, and video, which may be harder to process.
• Big Data: Datasets too large to be processed by conventional databases. Characteristics are: Volume, Velocity, Variety, Veracity.

Knowledge Discovery in Databases (KDD)

• Processes to extract useful information from databases for analysis and patterns.

Data Mining

• Extracting patterns and knowledge from data.

Conclusion:

• Provides a comprehensive overview of the subject matter, with detailed points and multiple perspectives.

Test your knowledge on audio file characteristics, operating system functions, and technology related to mobile applications. This quiz covers sample rates, bit rates, and the roles of different system components. Challenge yourself with matching terms and concepts in this technical assessment.