Computer Basics: Hardware, CPU and Software

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• A computer is an electronic device that manipulates information or data.
• It has the ability to store, retrieve, and process data.

Computer Components

• Hardware: The physical components of a computer system, such as the monitor, keyboard, mouse, hard drive, and motherboard.
• Software: The set of instructions or programs that tell the hardware what to do (e.g., operating systems, applications).
• Firmware: A specific class of computer software that provides the low-level control for the device's specific hardware.

Hardware

Central Processing Unit (CPU)

• The primary component of a computer that processes instructions.
• Often referred to as the "brain" of the computer.
• Consists of the control unit (CU), arithmetic logic unit (ALU), and registers.
  • Control Unit: Fetches instructions from memory and decodes them.
  • Arithmetic Logic Unit (ALU): Performs arithmetic and logical operations.
  • Registers: Small, fast storage locations used to hold data and instructions during processing.
• CPU performance is measured in clock speed (GHz) and the number of cores.

Memory

• Used to store data and instructions for the CPU to access.
• Random Access Memory (RAM): Volatile memory that stores data temporarily while the computer is running.
  • Faster to access than hard drives or SSDs.
  • Data is lost when the computer is turned off.
• Read-Only Memory (ROM): Non-volatile memory that stores permanent instructions, such as the BIOS.
  • Retains data even when the computer is turned off.

Storage Devices

• Used to store data persistently.
• Hard Disk Drive (HDD): Traditional storage device that uses spinning disks to store data magnetically.
  • Slower access times compared to SSDs.
  • Higher storage capacity per dollar.
• Solid State Drive (SSD): Storage device that uses flash memory to store data.
  • Faster access times and more durable than HDDs.
  • More expensive per unit of storage.

Input Devices

• Used to input data and commands into the computer.
• Examples: Keyboard, mouse, touch screen, microphone, scanner, camera.

Output Devices

• Used to display or output data from the computer.
• Examples: Monitor, printer, speakers, projector.

Motherboard

• The main circuit board of the computer that connects all the components.
• Provides slots and connectors for the CPU, RAM, storage devices, and expansion cards.

Graphics Card (GPU)

• Handles the processing and rendering of images and videos.
• Can be integrated into the motherboard or a separate expansion card.
• Important for gaming, graphic design, and video editing.

Power Supply Unit (PSU)

• Supplies power to all the components of the computer.
• Converts AC power from the wall outlet to DC power that the computer can use.

Software

Operating System (OS)

• Manages the hardware and software resources of the computer.
• Provides a user interface for interacting with the computer.
• Examples: Windows, macOS, Linux.

Application Software

• Programs designed to perform specific tasks.
• Examples: Word processors (e.g., Microsoft Word), web browsers (e.g., Chrome, Firefox), image editors (e.g., Photoshop), games.

System Software

• Software that supports the operation of the computer system.
• Includes operating systems, utilities, and device drivers.

Programming Languages

• Used to create software applications: examples are Python, Java, C++.

Computer Types

Desktop Computers

• Designed for use in a fixed location.
• Typically offer more power and expandability than laptops.

Laptop Computers

• Portable computers that combine the components of a desktop into a single unit.
• Designed for mobile use.

Tablets

• Mobile computers with a touch screen interface.
• Typically smaller and lighter than laptops.

Smartphones

• Mobile phones with advanced computing capabilities.
• Can run apps, browse the internet, and perform many of the same functions as a computer.

Servers

• Powerful computers designed to provide services to other computers over a network.
• Used for hosting websites, storing data, and running applications.

Mainframes

• Large, powerful computers used by organizations to process large amounts of data.
• Typically used in banking, finance, and government.

Supercomputers

• Extremely powerful computers designed for scientific and engineering calculations.
• Used for weather forecasting, simulations, and research.

Computer Architecture

Von Neumann Architecture

• A computer architecture that uses a single address space for both instructions and data.
• Most modern computers are based on this architecture.
• Key Feature: Shared memory for both program instructions and data

Harvard Architecture

• A computer architecture that uses separate address spaces for instructions and data.
• Allows for simultaneous access to instructions and data, improving performance.
• Often used in embedded systems and digital signal processing (DSP).

Data Representation

Binary System

• A number system that uses only two digits: 0 and 1.
• Computers use the binary system to represent all data and instructions.

Bits and Bytes

• Bit: The smallest unit of data in a computer, representing either 0 or 1.
• Byte: A group of 8 bits. Commonly used to represent characters, numbers, and other data.

Data Encoding

• Schemes used to represent characters, numbers, and other data in binary format.
• ASCII: A character encoding standard for representing text.
• Unicode: A more comprehensive character encoding standard that supports a wider range of characters and languages.

Computer Networks

Local Area Network (LAN)

• A network that connects computers and devices in a limited area, such as a home, office, or school.

Wide Area Network (WAN)

• A network that connects computers and devices over a large geographic area, such as a city, country, or the world.
• The Internet is the largest WAN.

Internet

• A global network of interconnected networks that use the Internet Protocol (IP) to communicate.

Network Protocols

• Sets of rules that govern how data is transmitted over a network.
• Examples: TCP/IP, HTTP, DNS.

Computer Security

Malware

• Malicious software designed to harm or disrupt computer systems.
• Examples: Viruses, worms, Trojans, ransomware.

Firewalls

• Security systems that monitor and control network traffic to prevent unauthorized access.

Antivirus Software

• Software designed to detect and remove malware from a computer.

Encryption

• The process of encoding data so that it is unreadable to unauthorized users.
• Used to protect sensitive information, such as passwords and financial data.

Authentication

• The process of verifying the identity of a user or device.
• Examples: Passwords, biometrics, multi-factor authentication.

Learn the fundamentals of computers, including hardware components like the CPU, software applications, and firmware. Understand the functions of the Control Unit, Arithmetic Logic Unit (ALU), and registers within the CPU.