Please enable JavaScript.
Coggle requires JavaScript to display documents.
How a Computer System Works from Binary to the Web - Coggle Diagram
How a Computer System Works from Binary to the Web
Binary Number Systems
Place values are powers of 2
Hexadecimal (base-16) = shorthand for binary
Everything stored as 0s and 1s (bits); 8 bits = 1 byte
ASCII/Unicode: how text becomes binary
Images stored as pixels → RGB values → binary
Lossy vs lossless compression (JPEG vs PNG)
Computer Architecture and Processing
Cache: fastest, smallest; sits between CPU and RAM
RAM: short-term memory (fast, temporary)
Cache → RAM → Storage (speed vs capacity tradeoff)
Storage (HDD/SSD): long-term memory (slow, permanent)
32-bit vs 64-bit processors
Clock speed (GHz) = cycles per second
GPU: handles graphics and parallel processing
Motherboard connects all components
Input/output devices (keyboard, monitor)
CPU = fetches, decodes, executes instructions (fetch-decode-execute cycle)
Operating Systems and Interfaces
Memory management: OS allocates RAM to programs
Unix/Linux vs Windows vs macOS
Kernel = core of OS; talks directly to hardware
MS-DOS: early CLI example
OS manages hardware and software (macOS, Windows, Linux)
File system: how OS organizes data
Process management: OS runs multiple programs at once
CLI vs GUI: two ways to interact with OS
CLI: text commands, direct hardware control, more powerful
GUI: visual elements, easier for everyday users
Shell = interface between user and OS
Computer Networks
IP address = unique identifier for each device on a network
MAC address = hardware-level identifier (vs IP which is network-level)
LAN (local) vs WAN (wide area)
Packets: data broken into chunks; each has a header (addresses) + payload (data)
Network = computers connected to share data
Bandwidth vs latency
Firewall: filters incoming/outgoing traffic
TCP/IP: core protocol suite
TCP: ensures packets arrive correctly and in order
IP: handles addressing and routing
Protocols = agreed rules for communication
OSI model — 7 layers (Physical, Data Link, Network, Transport, Session, Presentation, Application)
Router: directs traffic between networks
DNS: translates domain names → IP addresses
World Wide Web
Web ≠ internet (internet = infrastructure; web = service running on it
URL structure: protocol + domain + path
HTTP/HTTPS: protocol for sending web pages
HTTPS uses SSL/TLS encryption for security
Client-server model: browser requests, server responds
Web server software: Apache, Nginx
HTML = structure, CSS = style, JavaScript = behavior
Static vs dynamic web pages
Cookies and sessions: how websites remember you
APIs: how web services communicate with each other
Search engines vs the web itself
Hyperlinks = what makes it a "web"
How a page loads:
You type a URL
DNS looks up the IP address
Browser sends HTTP request to server
Server sends back HTML/CSS/JS
Browser renders the page