First Boot — Week 1A
Computer Fundamentals
What a computer actually is, what is inside it, and how the parts work together.
13 slides ~15 minutes CGS1000C · Forge
By the end of this lesson, you will be able to identify hardware components, distinguish hardware from software, and explain how data moves through a computer.
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What Is a Computer?
A machine that follows the IPOS cycle: Input → Processing → Output, with Storage holding data between cycles.
Input
You give the computer something: a keystroke, a click, a voice command, a file from a USB drive.
Processing
The CPU performs calculations and runs instructions, using RAM as a fast workspace.
Output
The result becomes something you can see, hear, or use: pixels on screen, audio, a printed page.
Storage
Data that needs to survive after power-off goes to a drive: documents, photos, the operating system itself.
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Hardware vs. Software
Two layers, one machine. Hardware is the physical body; software is the instructions that tell it what to do.
Hardware (the physical)
Anything you can touch. The case, the motherboard, CPU, RAM modules, hard drive, monitor, keyboard, cables, fans. Hardware is fixed at purchase — you cannot upgrade it by downloading something.
Software (the instructions)
Programs and data stored as files. The operating system, web browser, Word, games, photos, music. Software runs on hardware and can be installed, updated, or deleted without changing the physical machine.
The stack: Applications run on top of the operating system. The operating system runs on top of hardware. You see the application; everything below is invisible until something breaks.
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The CPU — The Brain
The Central Processing Unit fetches instructions, decodes them, and executes — billions of times per second.
Cores
Independent processing units. A 4-core CPU can do 4 things at once. Modern CPUs have 4-32+ cores.
Clock Speed
Measured in GHz. A 3.0 GHz CPU runs 3 billion cycles per second. Higher = faster (with the same architecture).
Cache
Tiny ultra-fast memory inside the CPU (L1, L2, L3). Holds frequently-used data so the CPU does not wait on RAM.
Brand families: Intel Core (i3, i5, i7, i9) and AMD Ryzen dominate desktops/laptops. Apple Silicon (M1/M2/M3) is ARM-based. Mobile devices use ARM CPUs from Qualcomm, Apple, MediaTek.
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Memory Hierarchy
Not all memory is the same. Faster memory is smaller and more expensive. The pyramid balances speed with cost.
Volatile vs persistent: RAM is volatile — it loses everything when power is cut. Storage (SSD, HDD) is persistent — it keeps your files when you shut down. That is why "save your work" matters.
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Storage Types
Where your files live when the power is off. Each type has a place: speed, capacity, portability, or cost.
HDD
Spinning magnetic platters. Cheap per GB. Slower than SSD. Sizes: 500 GB-20 TB. Mechanical — can fail if dropped.
SSD / NVMe
Solid-state flash memory. 5-50x faster than HDD. No moving parts. Standard in modern laptops. 256 GB-4 TB common.
USB / SD
Removable flash. Portable, slower than internal SSDs. USB sticks 16 GB-1 TB. SD cards for cameras, phones, Pi.
Cloud
Files stored on remote servers (OneDrive, iCloud, Google Drive). Access from anywhere with internet. Subscription-based.
The big shift: Since 2015, SSDs have replaced HDDs as the default boot drive. A 5-year-old laptop becomes usable again with a $50 SSD upgrade.
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Input Devices
How information gets into the computer. Different devices for different tasks.
Keyboard
Primary text input. Layouts: QWERTY (US), AZERTY (FR), Dvorak. Mechanical (loud, durable) vs membrane (quiet, cheap).
Pointing Devices
Mouse, trackpad, trackball, stylus. Translate physical motion into screen coordinates. Resolution measured in DPI.
Touch & Gesture
Touchscreens (phones, tablets, 2-in-1 laptops). Capacitive sensing detects finger contact. Multi-touch enables pinch, swipe.
Voice / Audio
Microphones + speech recognition. Cortana, Siri, Alexa. Increasingly used in accessibility, dictation, smart speakers.
Cameras / Scanners
Webcams for video, document scanners for paper, barcode/QR scanners for retail and inventory.
Sensors
Fingerprint readers, GPS, accelerometers, gyroscopes. Built into phones, laptops, and IoT devices.
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Output Devices
How the computer shows you the result. Visual, audio, and physical output.
Display (Monitor / Screen)
Resolution: 1080p (FHD), 1440p (QHD), 2160p (4K). Panel types: IPS (color accuracy), VA (contrast), TN (fast for gaming), OLED (perfect blacks). Refresh rate: 60 Hz standard, 120-240 Hz for gaming.
Audio (Speakers / Headphones)
Wired (3.5 mm jack) or wireless (Bluetooth). Built-in laptop speakers are usually weak; external speakers or headphones improve quality. Sound cards or DAC chips control audio output.
Printer
Inkjet: color photos, low volume, expensive ink. Laser: sharp text, high volume, cheaper per page. 3D printer: physical object output by extruding plastic layer by layer.
Projector / TV / Smart Display
Big-screen output for presentations, classrooms, conference rooms. Connect via HDMI, DisplayPort, USB-C, or wirelessly via Miracast / AirPlay / Chromecast.
Resolution and DPI: A 4K display has 3840×2160 pixels — 4× more than 1080p. Higher resolution shows finer detail but needs more GPU power and a bigger panel to be visible.
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Operating Systems
The OS is the manager that lets applications use hardware safely. Without it, the machine is just silicon.
Windows
Microsoft. Most common on desktops and laptops worldwide (~70% market share). Latest: Windows 11. Strong app ecosystem, gaming, business compatibility.
macOS
Apple. Pre-installed on Mac laptops and desktops. Unix-based core. Polished UI, tight hardware integration, popular with creatives and developers.
Linux
Open source kernel + many distributions (Ubuntu, Fedora, Debian, Mint). Free, customizable, dominant on servers, cloud, and embedded devices.
Android
Google. Linux-based. Most used mobile OS globally (~70% of smartphones). Open-source core, customized by phone makers.
iOS / iPadOS
Apple. Powers iPhones and iPads. Closed ecosystem, tightly controlled App Store, strong privacy/security defaults.
ChromeOS
Google. Browser-first OS for Chromebooks. Cheap, easy to manage, popular in K-12 schools.
What the OS actually does: Manages memory, schedules CPU time across programs, talks to hardware via drivers, enforces user permissions, provides the file system, and shows you a desktop or home screen.
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Files & File Systems
Every piece of data on a computer is a file. The file system organizes them into folders so you can find them.
Path
A path is the file's address. C:\Users\Maya\Documents\essay.docx tells the OS exactly where to find it.
Extension
The dot-suffix (.docx, .png, .exe) tells the OS what app to open the file with.
File System Type
NTFS (Windows), APFS (macOS), ext4 (Linux), exFAT (cross-platform USB drives). The OS chooses one when the drive is formatted.
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Software Categories
Not every program is the same kind of program. They sit in different layers and serve different roles.
System Software
The operating system itself, plus utilities that come with it: file explorer, task manager, command prompt. Manages the machine and lets other software run.
Application Software
What you launch to get work done: Word, Excel, Chrome, Photoshop, Spotify, Steam games. End-user-focused. Installs on top of the OS.
Utility Software
Single-purpose helpers: antivirus, disk cleaner, backup tool, file compression (7-Zip), screenshot tools. Often free or built into the OS.
Drivers & Firmware
Drivers translate between OS and hardware (printer driver, GPU driver). Firmware is software baked into hardware (BIOS/UEFI, router firmware). Both run below the user-visible apps.
Licensing models: Proprietary (Windows, Office — you pay for it), Free (free of charge but closed source), Open Source (source code public, free to modify — Linux, Firefox), SaaS (subscription, runs in browser — Microsoft 365, Google Workspace).
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Networks & The Internet
A computer is far more useful when it can talk to other computers. The network is the connection layer.
LAN
Local Area Network. Your home or office. Connected by Ethernet cable or Wi-Fi to a single router.
WAN / Internet
Wide Area Network. The internet is the largest WAN: a network of networks spanning the globe.
IP Address
Every device on a network has an address. Example: 192.168.1.10 (private) or 142.250.190.78 (public).
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Week 1A Summary
Computer Fundamentals — the foundation everything else builds on.
1IPOS cycle: Input → Processing → Output, with Storage holding data between cycles.
2Hardware vs software: Hardware is physical; software is instructions. Apps run on the OS, the OS runs on hardware.
3CPU cycle: Fetch → Decode → Execute, billions of times per second. Cores + clock speed + cache define performance.
4Memory hierarchy: Registers → Cache → RAM → SSD → HDD/Cloud. Faster = smaller and pricier per GB.
5Volatile vs persistent: RAM forgets when powered off; storage remembers. Save your work.
6OS choices: Windows, macOS, Linux for desktops; Android and iOS for mobile; ChromeOS for browser-first machines.
7Files have paths and extensions: C:\Users\Maya\report.docx. The extension tells the OS which app to open.
8Networks: LAN at home, WAN/Internet across the globe. Routers link your LAN to your ISP to the internet.
Next up: Week 1B — Word Processing Basics. Open Microsoft Word, format text, save your first document.