Computer Hardware
Understanding the physical components that make up a computer system.
The CPU processes instructions, performs calculations, and manages data flow within the computer. Key specifications include:
- Clock speed (GHz) - how many cycles per second
- Cores - number of processing units
- Cache - high-speed memory for quick data access
- Architecture (32-bit vs 64-bit)
RAM stores data that the CPU is actively using. It's volatile, meaning data is lost when power is turned off. Key specifications include:
- Capacity (GB) - amount of storage
- Speed (MHz) - how quickly data can be accessed
- Type (DDR4, DDR5) - generation of memory technology
- Channels - pathways for data transfer
Storage devices keep data even when the computer is powered off. Common types include:
- HDD (Hard Disk Drive) - mechanical storage
- SSD (Solid State Drive) - faster flash storage
- NVMe - ultra-fast storage connected via PCIe
- Optical drives (CD/DVD/Blu-ray)
The motherboard connects all components together and allows them to communicate. Key features include:
- Form factor (ATX, Micro-ATX, Mini-ITX)
- CPU socket type
- Chipset - determines compatibility and features
- Expansion slots (PCIe) for add-in cards
The GPU handles rendering images, videos, and animations. Key specifications include:
- VRAM (Video RAM) - dedicated graphics memory
- Core count - number of processing units
- Clock speed - operating frequency
- Architecture - design generation
The PSU converts AC power from the wall outlet to DC power for computer components. Key specifications include:
- Wattage - maximum power output
- Efficiency rating (80+ Bronze, Gold, Platinum)
- Modularity - detachable cables
- Form factor - physical size and shape
Computing Fundamentals
Understanding the basic concepts that power computing systems.
Computers use the binary number system, which has only two digits: 0 and 1. Each digit is called a bit (binary digit). Computers use binary because electronic components can easily represent two states: on (1) or off (0).
Binary to Decimal Conversion
Each position in a binary number represents a power of 2, starting from the rightmost digit (2^0 = 1).
| Binary | Calculation | Decimal |
|---|---|---|
| 0001 | 0×8 + 0×4 + 0×2 + 1×1 | 1 |
| 0010 | 0×8 + 0×4 + 1×2 + 0×1 | 2 |
| 0101 | 0×8 + 1×4 + 0×2 + 1×1 | 5 |
| 1000 | 1×8 + 0×4 + 0×2 + 0×1 | 8 |
| 1101 | 1×8 + 1×4 + 0×2 + 1×1 | 13 |
Common Binary Units
- BitA single binary digit (0 or 1)
- Byte8 bits (can represent 256 values)
- Kilobyte (KB)1,024 bytes
- Megabyte (MB)1,024 kilobytes
- Gigabyte (GB)1,024 megabytes
- Terabyte (TB)1,024 gigabytes
- Petabyte (PB)1,024 terabytes
ASCII and Unicode
Computers represent text using character encoding standards:
- ASCII - 7-bit encoding for basic Latin characters
- Unicode - supports characters from all writing systems
- UTF-8 - variable-width encoding for Unicode
Color Representation
Colors are typically represented using RGB values:
- Each color has Red, Green, and Blue components
- Each component ranges from 0-255 (8 bits)
- 24-bit color allows for 16.7 million colors
- Example: RGB(255, 0, 0) represents pure red
Image and Sound
Digital media is represented as binary data:
- Images are grids of pixels with color values
- Resolution determines image quality (e.g., 1920×1080)
- Sound is represented as waveform samples
- Sample rate (Hz) and bit depth affect audio quality
Von Neumann Architecture
Most computers follow the Von Neumann architecture with these components:
- CPU (Central Processing Unit)
- Memory (RAM)
- Input/Output devices
- Storage
- System bus for communication between components
CPU Operation
The CPU follows the fetch-decode-execute cycle:
- Fetch instruction from memory
- Decode the instruction
- Execute the instruction
- Store results
32-bit vs 64-bit Computing
The bit architecture affects system capabilities:
- Refers to the size of data chunks processed
- 32-bit systems can address up to 4GB of RAM
- 64-bit systems can address theoretically 18 exabytes
- 64-bit enables more efficient processing of large data
Peripheral Devices & Interfaces
Understanding the devices that connect to your computer and how they communicate.
USB (Universal Serial Bus)
The most common connection interface for peripherals:
- USB 2.0: 480 Mbps transfer speed
- USB 3.0/3.1: 5-10 Gbps transfer speed (blue ports)
- USB-C: Reversible connector with up to 40 Gbps (Thunderbolt)
- Supports plug-and-play functionality
HDMI & DisplayPort
Video and audio output interfaces:
- HDMI: Common for TVs and monitors, supports 4K/8K
- DisplayPort: Higher bandwidth, better for high refresh rates
- Both carry digital video and audio signals
Wireless Interfaces
Connections without physical cables:
- Bluetooth: Short-range wireless for peripherals
- Wi-Fi: Wireless networking
- NFC: Near Field Communication for close proximity data exchange
Input Devices
Devices that send data to the computer:
- Keyboard: Text and command input
- Mouse/Trackpad: Cursor control and navigation
- Microphone: Audio input
- Webcam: Video input
- Scanner: Document and image input
- Game controllers: Specialized input for gaming
Output Devices
Devices that receive data from the computer:
- Monitor/Display: Visual output
- Speakers/Headphones: Audio output
- Printer: Physical document output
- Projector: Large-scale visual output
| Device Type | Common Interfaces | Connection Tips |
|---|---|---|
| Keyboard & Mouse | USB, Bluetooth, PS/2 (legacy) | USB ports are interchangeable; wireless devices need batteries |
| Monitor | HDMI, DisplayPort, VGA (legacy), DVI (legacy) | Use digital connections (HDMI/DisplayPort) for best quality |
| Printer | USB, Wi-Fi, Ethernet | Network printers can be shared among multiple computers |
| External Storage | USB, Thunderbolt, eSATA | Use USB 3.0+ for faster data transfer speeds |
| Audio Devices | 3.5mm audio jack, USB, Bluetooth | Color-coded jacks: green (output), pink (mic), blue (line-in) |
| Networking | Ethernet, Wi-Fi | Wired connections are more stable than wireless |
PC Terminology Glossary
Common terms and acronyms you'll encounter in the world of computing.