Computer Basics: Hardware and Software

• A computer is an electronic tool for processing data and information.
• Computers are capable of data storage, retrieval, and processing.

Components of a Computer

• Hardware: The physical components of a computer system.
• Software: Instructions dictating the operations a computer's hardware performs.
• Input Devices: These devices feed data and control commands into a computer, like keyboards and mice.
• Output Devices: These display or output data from a computer, such as monitors and printers.

Hardware Components

• Central Processing Unit (CPU): It's the computer's processing center, responsible for executing instructions.
  • The CPU manages arithmetic, logical, and control functions.
  • Clock speed (GHz) and core count are key CPU performance indicators.
• Memory (RAM): This is a short-term storage used by the CPU for immediate data and tasks.
  • RAM is volatile, meaning data is lost without power.
  • RAM capacity is measured in gigabytes (GB).
• Storage Devices: These provide long-term storage for data and programs.
  • Hard Disk Drive (HDD): HDDs use magnetic platters for mechanical data storage.
  • Solid State Drive (SSD): SSDs utilize flash memory for faster and more durable electronic storage, compared to HDDs.
  • USB Flash Drives: Portable flash memory storage devices.
• Motherboard: It serves as the main circuit board, connecting all computer components.
  • The motherboard includes sockets and slots for the CPU, RAM, and expansion cards.
• Graphics Card (GPU): For image and video processing.
  • GPUs can be integrated on the motherboard or added as separate expansion cards.
• Power Supply Unit (PSU): It supplies power to all computer components.

Software Components

• Operating System (OS): It manages the computer's hardware and software resources.
  • The OS provides a platform for applications to run.
  • Windows, macOS, and Linux are common operating systems.
• Application Software: Programs designed for specific tasks.
  • Examples include word processors, web browsers, and games.
• System Software: This software supports the OS and aids in managing computer resources.
  • Device drivers and utilities are types of system software.

Computer Types

• Desktop Computers: Designed for stationary use.
• Laptop Computers: Portable computers that combine the screen and keyboard in one unit.
• Tablets: Mobile devices operated through a touchscreen.
• Smartphones: Mobile phones with advanced computing.
• Servers: Robust computers providing services to other computers on networks.
• Mainframes: Powerful computers used by organizations for critical applications and large data tasks.
• Supercomputers: Extremely powerful computers designed for complex calculations and simulations.

Computer Architecture

• Von Neumann Architecture: This architecture uses a single address space for both instructions and data.
  • The majority of modern computers utilize this setup.
  • The CPU, memory, and input/output devices are key components.
• Harvard Architecture: Employs separate address spaces for instructions and data.
  • This architecture is often found in embedded systems and digital signal processing.

Data Representation

• Binary System: A base-2 number system using 0 and 1.
  • Computers use binary code for all data and instructions.
• Bits and Bytes:
  • Bit: The smallest data unit, represented by 0 or 1.
  • Byte: A group of 8 bits representing characters, numbers, and other data.
• Data Types:
  • Integer: Represents whole numbers.
  • Floating-Point: Represents numbers containing decimal points.
  • Character: Letters, symbols, and numbers, represented by encodings like ASCII and Unicode.
  • Boolean: True or false values.

Computer Networks

• Local Area Network (LAN): Connects computers in a limited area like a home, school, or office.
• Wide Area Network (WAN): Connects computers across a large geographical area, like the Internet.
• Internet: A global network connecting countless networks.
• Network Protocols: Govern data transmission over a network.
  • TCP/IP: It is the foundation of the Internet, designed for reliable device communication.
  • HTTP: Transfers web pages and content.
  • FTP: Transfers files.

Operating Systems

• Windows: Microsoft's proprietary OS.
• macOS: Apple's proprietary OS for Macintosh computers.
• Linux: An open-source OS popular for servers, desktops, and embedded systems.
• Kernel: The core of the OS manages system resources.
• User Interface (UI): It's the means of user interaction with the OS.
  • Graphical User Interface (GUI): Utilizes windows, icons, and menus.
  • Command-Line Interface (CLI): Employs text-based commands.

Programming Languages

• High-Level Languages: Easy to read and write, like Python, Java, and C++.
• Low-Level Languages: Closer to the hardware, demanding detailed computer architecture knowledge, such as Assembly Language.
• Compiler: Translates high-level code into machine code.
• Interpreter: Executes high-level code directly, without prior compilation.

Computer Security

• Malware: Software designed for malicious purposes like harming or disrupting computer systems.
  • Viruses: Malware that replicates and spreads to other files or computers.
  • Worms: Self-replicating malware spreading across networks without user action.
  • Trojans: Malware disguised as legitimate software to deceive users into installing them.
  • Spyware: Collects user data without consent.
  • Ransomware: Encrypts user files, demanding ransom for their release.
• Firewall: A security system that monitors and controls network traffic, preventing unauthorized access.
• Antivirus Software: Detects and removes malware.
• Encryption: Encoding data to prevent unauthorized access.
• Authentication: Verifying user or device identity.
  • Passwords: Used for user authentication.
  • Multi-Factor Authentication (MFA): Requires different identification methods for user authentication.

Database Management Systems (DBMS)

• Database: Organized data collection.
• Relational Database: Data organized in tables with rows and columns.
  • MySQL, PostgreSQL, and Oracle are examples.
• NoSQL Database: A database that does not use the relational model.
  • MongoDB and Cassandra are examples.
• SQL (Structured Query Language): Used for managing and querying relational databases.

Cloud Computing

• Cloud Computing: Delivery of computing services via the Internet.
• Infrastructure as a Service (IaaS): Provides access to computing resources, like servers and networks.
  • Amazon Web Services (AWS) and Microsoft Azure are examples.
• Platform as a Service (PaaS): Provides a platform for app development, running, and management.
  • Google App Engine and Heroku are examples.
• Software as a Service (SaaS): Provides access to software applications over the Internet.
  • Salesforce and Google Workspace are examples.

Future Trends

• Artificial Intelligence (AI): Computer systems performing tasks typically requiring human intelligence.
• Machine Learning (ML): A subset of AI, enabling computers to learn from data without explicit programming.
• Internet of Things (IoT): Network of interconnected devices collecting and exchanging data.
• Quantum Computing: Computing that applies quantum mechanics to solve problems beyond classical computer capabilities.
• Blockchain: Distributed ledger tech enabling secure, transparent transactions.