Computer Science Fundamentals
Interactive Learning Experience
Hardware Components
CPU, RAM, ROM, and system architecture
Software Systems
System vs Application software
Storage Devices
HDD, SSD, optical, and magnetic storage
Databases
Tables, forms, queries, and relationships
Hardware Components
Understanding the physical components of computer systems
Central Processing Unit (CPU)
ALU
Arithmetic Logic Unit
Control Unit
Instruction Processing
Two Main Components of CPU:
1. Arithmetic Logic Unit (ALU)
- Performs mathematical calculations (addition, subtraction, multiplication, division)
- Executes logical operations (AND, OR, NOT)
- Handles comparison operations
2. Control Unit
- Fetches instructions from memory
- Decodes instructions into executable operations
- Controls the flow of data between CPU components
- Coordinates with other system components
Memory Comparison: RAM vs ROM
RAM (Random Access Memory)
ROM (Read-Only Memory)
| Characteristic | RAM | ROM |
|---|---|---|
| Volatility | Volatile - loses data when power is off | Non-volatile - retains data without power |
| Access Type | Read and Write operations | Read-only operations |
System Unit: Motherboard & CPU Interaction
How Motherboard and CPU Work Together:
Power Distribution: Motherboard provides power to CPU through voltage regulators
Data Pathways: Motherboard's buses carry data between CPU, RAM, and other components
Clock Signals: Motherboard's clock generator synchronizes all operations
Communication: Chipset on motherboard manages data flow and component communication
Software Systems
Understanding different types of software and their functions
System Software vs Application Software
System Software
Purpose: Manages and controls computer hardware
Example: Windows 11, macOS, Linux
- Controls hardware resources
- Provides platform for other software
- Manages files and security
Application Software
Purpose: Performs specific tasks for users
Example: Microsoft Word, Google Chrome
- Designed for end-user tasks
- Runs on top of system software
- Provides specific functionality
Spreadsheet: Formulas vs Functions
| A | B | C | |
|---|---|---|---|
| 1 | 10 | 20 | =A1+B1 |
| 2 | 5 | 15 | =SUM(A2:B2) |
Formula
Definition: A user-created expression using cell references and operators
Example: =A1+B1
Calculates: 10 + 20 = 30
Function
Definition: Pre-built formula that performs specific calculations
Example: =SUM(A2:B2)
Calculates: SUM(5, 15) = 20
Storage Devices
Understanding different types of storage technologies
Why Secondary Storage is Necessary
Permanent Data Storage
RAM is volatile - data is lost when power is turned off. Secondary storage preserves data permanently.
Large Capacity
Provides much larger storage capacity than RAM at a lower cost per byte.
Program Storage
Stores operating systems, applications, and user files that need to persist.
Hard Disk Drives (HDD) vs Solid State Drives (SSD)
Hard Disk Drive (HDD)
Technology:
- Magnetic storage on spinning disks
- Mechanical read/write heads
- Moving parts create noise and heat
Solid State Drive (SSD)
Technology:
- Flash memory chips
- No moving parts
- Electronic data access
SSD Advantages over HDD:
Speed
Much faster data access and transfer rates due to no mechanical parts
Durability
More resistant to physical shock and vibration without moving parts
Three Types of Secondary Storage
Magnetic Disk Storage
Example: Hard Disk Drive (HDD)
Characteristics:
- Data stored as magnetic fields
- High capacity, moderate speed
- Mechanical moving parts
Use Case: Bulk storage for computers, servers, backup systems
Optical Disc Storage
Example: Blu-ray Disc
Characteristics:
- Data stored as pits and lands
- Read by laser light
- Removable and portable
Use Case: Movie distribution, software installation, archival storage
Solid-State Storage
Example: SSD, USB Flash Drive
Characteristics:
- Data stored in flash memory
- Very fast access times
- No moving parts
Use Case: OS drives, gaming, portable storage, enterprise systems
Magnetic vs Optical Storage
Magnetic Storage
How it works: Data stored by magnetizing tiny areas on a magnetic surface
Example: Hard Disk Drive (HDD), Magnetic Tape
Optical Storage
How it works: Data stored as microscopic pits and lands, read by laser light
Example: CD, DVD, Blu-ray Disc
Input & Output Devices
Understanding how we interact with computer systems
Input Devices vs Output Devices
Input Devices
Definition: Devices that allow users to enter data and commands into the computer
Example: Keyboard - used to input text, numbers, and commands
Output Devices
Definition: Devices that display or present processed information from the computer
Example: Monitor - displays visual information, text, and graphics
Input Device Categories
Keyboarding Device
Device: Keyboard
Function: Text and command input
Usage: Typing documents, programming, system commands
Pointing Device
Device: Mouse
Function: Cursor control and selection
Usage: Navigation, clicking, dragging, graphical interfaces
Scanning Device
Device: Scanner
Function: Image and document digitization
Usage: Converting physical documents to digital format
Soft Copy vs Hard Copy Output
Soft Copy
Definition: Digital output displayed on screen that cannot be physically touched
Example Device: Monitor/Display Screen
- Temporary display
- Can be easily modified
- Environmentally friendly
Hard Copy
Definition: Physical output printed on paper or other tangible medium
Example Device: Printer
- Physical document
- Permanent record
- Portable without technology
Monitor Display Quality Features
Resolution
Description: Number of pixels displayed (width × height)
Impact: Higher resolution = sharper, more detailed images
Examples: 1080p (1920×1080), 4K (3840×2160)
Refresh Rate
Description: How many times per second the display updates (Hz)
Impact: Higher refresh rate = smoother motion, less flicker
Examples: 60Hz (standard), 144Hz (gaming), 240Hz (professional)
Common Connection Ports
USB Port
Full Name: Universal Serial Bus
Uses: Keyboards, mice, storage devices, printers, smartphones
Features: Hot-swappable, power delivery, data transfer
HDMI Port
Full Name: High-Definition Multimedia Interface
Uses: Monitors, TVs, projectors, audio/video devices
Features: Digital audio/video, high-definition support
Connectivity in Information Technology
What is Connectivity?
Connectivity refers to the ability of computer systems, devices, and networks to communicate and share information with each other.
Example: Wi-Fi Connection
A laptop connecting to the internet through a Wi-Fi router, enabling access to online resources and communication with other devices worldwide.
Database Systems
Understanding data organization and management
Data vs Information
Data
Raw facts and figures
Individual numbers, text, dates without context
Information
Processed, organized, meaningful data
Data that has been analyzed and provides insights
Primary Key in Database Tables
| Student_ID (PK) | First_Name | Last_Name | |
|---|---|---|---|
| S001 | John | Smith | john.smith@email.com |
| S002 | Mary | Johnson | mary.johnson@email.com |
| S003 | David | Brown | david.brown@email.com |
Purpose of Primary Key:
- Unique Identification: Each record has a unique identifier
- No Duplicates: Ensures no two records have the same primary key value
- Data Integrity: Maintains consistency and prevents data corruption
- Relationships: Used to link tables together in relational databases
Fields vs Records Relationship
| Field: ID | Field: Name | Field: Grade | Field: Subject |
|---|---|---|---|
| 001 | Alice Johnson | A+ | Mathematics |
| 002 | Bob Smith | B | Science |
Fields (Columns)
- Individual data categories or attributes
- Define the type of data stored
- Examples: Name, Age, Address, Phone
Records (Rows)
- Complete set of related data
- One instance of all fields combined
- Represents one entity (person, product, etc.)
Relational Database Building Blocks
Tables
Purpose: Store data in organized rows and columns
Example: Student table with ID, Name, Grade fields
Forms
Purpose: User-friendly interface for data entry and editing
Example: Student registration form with input fields
Queries
Purpose: Retrieve and filter specific data from tables
Example: Find all students with grade 'A' in Mathematics
Student Information System Example:
Tables store student data (personal info, grades, courses)
Forms allow staff to add new students or update information
Queries generate reports like "All students in Computer Science"
Networking & Internet
Understanding how computers communicate and connect
Domain Name System (DNS)
1. User Types URL
2. DNS Lookup
DNS Server
3. IP Address Returned
4. Website Loads
Function of DNS in Internet Browsing:
- Translation Service: Converts human-readable domain names to IP addresses
- Directory Service: Acts like a phone book for the internet
- User-Friendly Navigation: Allows users to remember websites by names instead of numbers
- Global Distribution: Distributed system ensures fast and reliable name resolution
Example: When you type "www.google.com", DNS translates it to "172.217.14.206" so your browser knows which server to connect to.
E-commerce
Understanding electronic commerce transactions and benefits
Common E-commerce Transaction Types
Business-to-Consumer (B2C)
Description: Businesses sell products/services directly to individual consumers
Examples: Amazon, eBay, online retail stores
Characteristics: Online shopping, digital payments, home delivery
Business-to-Business (B2B)
Description: Businesses sell products/services to other businesses
Examples: Wholesale platforms, supply chain management systems
Characteristics: Bulk orders, B2B portals, negotiated pricing
E-commerce Benefits for Business
Global Market Reach
Advantage: Businesses can reach customers worldwide without physical presence
- Access to international markets
- 24/7 availability across time zones
- No geographical limitations
Reduced Operating Costs
Advantage: Lower operational expenses compared to traditional retail
- Reduced rent and utility costs
- Lower staffing requirements
- Automated processes and transactions
Information Systems
Understanding the components that work together to process information
Five Components of Information Systems
Hardware
Physical components: computers, servers, networks, devices
Software
Programs and applications that process data and instructions
Data
Raw facts and information that the system processes
People
Users, IT specialists, and stakeholders who interact with the system
Procedures
Rules, policies, and instructions that govern system operation
Online Shopping Example - How Components Work Together:
Customer Browses Products
Hardware: Customer's computer/phone, web servers
Software: Web browser, e-commerce application
Data: Product catalog, prices, inventory
People: Customer browsing
Procedures: Website navigation rules
Payment Processing
Hardware: Payment servers, security systems
Software: Payment gateway, encryption software
Data: Customer payment information
People: Customer, payment processor
Procedures: Security protocols, payment verification
Order Fulfillment
Hardware: Warehouse systems, shipping equipment
Software: Inventory management, shipping software
Data: Order details, shipping information
People: Warehouse staff, delivery personnel
Procedures: Order processing, shipping protocols
System Unit Components: Launching Applications
Motherboard
Role: Communication hub connecting all components
CPU
Role: Executes program instructions
RAM
Role: Temporary storage for active programs
Application Launch Process:
User clicks application icon
Input travels through motherboard to CPU
CPU requests program data
Motherboard facilitates communication with storage
Program loaded into RAM
Motherboard manages data transfer to memory
CPU executes program instructions
RAM provides fast access to program data
Application interface appears
All components work together through motherboard