Computer Basics Overview

Computer Basics

• A computer is a machine that changes information from one form to another through input, processing, output, and storage.
• Computers turn data into raw, organized information.
• Two types of computers exist: analog and digital.
  • Analog computers measure data on a scale with many values.
  • Digital computers use data in digital or numerical form with a fixed value.
• Information processing cycle: the series of steps a computer performs to process data.
  • Input: raw information entered, including letters, numbers, and complex images. Input devices are used, including keyboards, mice, scanners, cameras, and microphones.
  • Bits of data are represented by 0 or 1. Off state = 0. On state = 1
  • Processing: the computer performs tasks with the data. Instructions are coded through binary. A program tells the computer what to do.
  • Output: presents results to the user, such as an image on the screen, audio, or a printed document.
  • Storage: saves information. Without permanent storage, the work done on a computer is lost.
    • Primary storage: Stores data and instructions temporarily while the computer is working. RAM is an example of primary storage.
    • Secondary storage: Stores data permanently. Examples of secondary storage include hard drives, SSDs and external storage devices.

Measurement Units

• Bit: the smallest unit in a computer (symbol: b). -A binary digit
• Byte: 8 bits (symbol: B). Represents a character, number, or symbol.
• Kilobyte (KB): 1,024 bytes.
• Megabyte (MB): 1,024 KB.
• Gigabyte (GB): 1,024 MB.
• Terabyte (TB): 1,024 GB.
• Computers use binary (base-2) to operate, but humans usually work with the decimal (base-10) system.

Hexadecimal System

• A hexadecimal number uses 16 possible values (0-F).
• Used to represent colors. Colors have 3 bytes of red, green and blue.
• Used to represent numeric values in a more concise way, and to represent colors on RGB based systems.

Encoding Tables

• Computers use encoding tables (like ASCII and Unicode) to represent text in a way they understand (binary).
• ASCII: Uses 8 bits to represent 256 characters, making it adequate for English.
• Unicode: Uses 16 bits to represent a much wider range of characters, suitable for many languages.

Computer Types

• Supercomputers: Large, most powerful computers and expensive. Used for complex calculations, especially in scientific research. Examples include weather forecasting, molecular research or simulations
• Mainframe computers: Used by many people simultaneously to access the same secure data. Typically used by large corporations and government agencies. Examples include banks and airline reservation
• Server: Manages data and resources for other computers on a network. Used in schools, universities and organizations
• Microcomputers (Personal computers):
  • Desktop computers: Reside on desks or tables.
  • Laptops: Portable versions of desktops that are used primarily for internet browsing
  • Netbooks: Small laptops that are typically carried.
  • Tablets: A computer that combines the features of a graphic tablet and personal computers, including touchscreen
  • Workstations: Powerful computers connected to a network and are often expensive. Used for tasks requiring extensive graphics or computational power.

Computer Hardware

• Hardware: The physical parts of a computer.
  • Motherboard: The primary circuit board that connects all the computer components.
  • CPU: The central processing unit (also called the processor) and is the computational engine of a computer.
  • RAM: Random Access Memory - A temporary storage space
  • Storage devices (HDD): Hard disk drives - A device for long-term storage of files.
  • Storage Devices (SSDs): Solid State Drives - A device for long-term storage of files.
  • Input/Output devices (I/Os): Devices used for input and output data, including keyboards, mouse, scanner, microphones, speakers, digital cameras, and monitors.

Measurement Units

• Bit: The smallest unit of data in a computer, typically represented as a 0 or a 1.
• Byte: A group of eight bits.
• Kilobyte (KB): 1,024 bytes.
• Megabyte (MB): 1,024 KB.
• Gigabyte (GB): 1,024 MB.
• Terabyte (TB): 1,024 GB.

Computer Software (General)

• Software: A set of instructions that tell a computer what tasks to perform.
  • System software: programs that help the computer run properly. Examples: operating system (OS) and utility programs.
  • Application software: Programs designed to perform specific tasks. Examples: word processors, spreadsheets, games, and web browsers.

Computer Software (System Software)

• Operating System: The most important system software managing computer resources. Process management, memory management, file system, device management, security, and a user interface are its functions.
• Utility Software: Performs maintenance and repair tasks, including disk defragmentation or antivirus scanning. Other kinds of utilities include those that help compress files, diagnostic tools or backup data.

Other Input Output Devices

• Keyboard: An input device for entering text and commands into a computer.
• Mouse: A pointing device for controlling a cursor on a computer screen and making selections.
• Scanner: A device that captures images.
• Microphone: An input device for capturing sounds, such as voice recordings.
• Speakers: An output device for sound reproduction that is used by computers.
• Digital Cameras: Capture and record images and videos.
• Webcam: A small video camera.
• Memory card: Used for storing data on mobile devices like smartphones and digital cameras.
• Ports and Connectors: Used for external peripheral devices. I/Os include, USB, Ethernet, HDMI, PS/2

Computer Software (Application Software)

• Software designed to perform specific tasks such as creating documents, storing information, or editing video is called application software. Examples include: word processing, spreadsheet, database, presentation, and communication programs. Also called productivity suites, they can be used in personal and professional uses.

Types of Application Software

• Productivity software: Software useful in work, school or home, used to manage tasks, calendars, or timers.
• Graphics software: used for creative fields, such as drawing, printing, photo editing.
• Communication software: Used for making internet connections and sending/receiving emails.
• Home/Education/Entertainment: Programs such as financial management or educational tools.

App Requirements

• Compatibility: the software might not work properly on a computer with an incompatible operating system.
• Hardware needs: some programs might need a certain type of processor or amount of memory or graphics card to work.
• Storage needs: Ensure there's enough disk space for the software, updates, and files.
• Documentation: helpful for troubleshooting or installing the software. There is online help or printed manuals.

Cloud Computing

• Cloud computing refers to computing services that are delivered over the Internet.
  • Cloud storage is a method for storing data on remote servers rather than local computers.
  • Software as a service (SaaS) provides access to applications over the internet via subscriptions.

Cloud Computing - Deployment Models

• Public Cloud: Data and computing resources are owned and operated by an external provider and made available to the public. Typically, cost-efficient
• Private Cloud: Data and computing resources are used exclusively by one organization and is maintained either on their own facilities, or from a third party provider. Often suited for large companies that need greater security and control.
• Community Cloud: Organizations with mutual needs share data and computing resources in a special cloud environment.
• Hybrid Cloud: Combinations of public and private clouds. Offers great flexibility and adaptability to your needs.

Virtualization

• Virtualization: The creation of virtual versions of computer resources (servers, storage, networks, etc.) to manage them more efficiently. Virtualization can improve resource use by running several virtual machines on one physical machine. Desktop virtualization allows you to run programs and applications separate from your main computer.

Cyber Security

• Cyber security is a set of practices to protect computers and networks from various attacks and threats.
• Malware: any software intentionally designed to cause damage.
• Viruses: Malware that copies itself and spreads to other files.
• Trojan Horses: Hidden within legitimate software.
• Worms: self-replicating malware that spreads across networks.
• Ransomware: Type of malware that locks computer files and then demands payment to unlock them.
• Spyware: Malware that secretly records user's activities without their knowledge.
• Keyloggers: Record keystrokes to steal sensitive information.

Cyber Security - General Best Practices

• Use strong, unique passwords that include numbers, uppercase/lowercase letters and symbols.
• Implement multi-factor authentication (MFA).
• Install, run and regularly update security and antivirus software and programs. Ensure your software is updated with the latest security patches.
• Regularly back up your important files using several methods – including cloud storage and hard drives. Ensure backups are secure and accessible after disaster recovery