Computer Essentials Overview

Computer Essentials

• A computer is an electronic device that receives, stores, processes, and outputs data based on instructions (programs).
• It combines hardware and software components to execute applications and solve problems.

Information Processing Cycle

• The core operations of a computer are often referred to as the information processing cycle.
• There are four basic actions:
  • Input: Data and instructions are entered into the computer using devices like keyboards, mice, scanners, cameras, and microphones.
  • Processing: The computer's central processing unit (CPU) processes the inputted data. This involves performing arithmetic or logic operations based on the instructions.
  • Output: The computer displays or outputs the results of the processed data. This can be in the form of a visual display on a monitor, printed on paper, played through speakers, saved to a file, or transmitted to another device. Output devices include monitors, printers, and speakers.

Storage

• After or during processing, the computer saves data in its memory.
• Primary Storage: Temporary storage, like RAM, for the CPU to access data and instructions while the computer is running.
• Secondary Storage: Long-term storage, like hard drives, solid-state drives (SSDs), or external storage devices, where data, applications, and the operating system reside.

Data vs. Information

• Data: Raw facts and figures without context. Examples include numbers, text, characters, or bits.
• Information: Data that has been processed and given meaning and purpose in a specific context.

Measurement Units

• Bit (b): The most basic unit of data, represented by 0 or 1.
• Byte (B): Consists of 8 bits and is the standard unit for representing characters, numbers, or symbols in computers. (1 Byte = 8 bits)
• Kilobyte (KB): 1,024 Bytes
• Megabyte (MB): 1,024 Kilobytes
• Gigabyte (GB): 1,024 Megabytes
• Terabyte (TB): 1,024 Gigabytes (and so on)

Transistors

• Transistors are electronic switches in computers.
• They represent binary values (0 and 1) in digital circuits.

Decimal and Hexadecimal Systems

• Computers primarily use binary (base-2) system, with 0s and 1s.
• The decimal system (base-10) is used for human interaction.
• The hexadecimal system (base-16) is used for concise representation of binary data, making conversions easier. The digits 0-9 are used, followed by A-F (or a-f), where A=10, B=11...F=15.

Color Representation (Web Design)

• Colors are represented as RGB values (Red, Green, Blue).
• Colors on the web are also represented using hexadecimal codes preceded by the hash (#).

Encoding Tables

• Computers use encoding tables (like ASCII and Unicode) to represent and manipulate textual information.
• ASCII: A 7-bit standard for representing 128 characters (letters, numbers, symbols, and control characters).
• Unicode: A much broader standard using 16 or 32 bits to represent a wider range of characters (including international characters and emojis).

Computer Types

• Supercomputers: Complex, high-end computations (e.g., weather forecasting, scientific simulations).
• Mainframe Computers: Handle large amounts of data simultaneously and support multiple users (e.g., transaction processing, bank systems).
• Servers: Provide data and resources to other computers (e.g., schools, companies, webservers, data centers).
• Workstations: Powerful computers for specialized tasks needing better graphics or computational power (e.g., video editing, 3D modeling).
• Microcomputers: Individual user devices—include desktops, laptops, tablets, and netbooks.