Cheatsheets & references

14 original reference sheets—definitions plus practical examples for every course.

Cheatsheets hub · Search cheatsheets

• Windows CheatsheetQuick reference for Command Prompt: navigation, files, search, system tools, networking, and batch basics.
• Linux CheatsheetQuick reference for everyday Linux terminal commands: navigation, files, search, permissions, packages, and networking.
• Python CheatsheetQuick reference for Python syntax, collections, control flow, functions, files, and errors.
• JavaScript CheatsheetQuick reference for JavaScript syntax, values, functions, DOM events, and async patterns.
• Java CheatsheetQuick reference for Java program structure, types, control flow, methods, classes, and common tools.
• C CheatsheetQuick reference for compiling C, types, control flow, functions, pointers, strings, and structs.
• SQL CheatsheetBeginner SQL quick reference for reading, filtering, joining, and changing data—examples work in SQLite and most other databases with small syntax tweaks.
• Git CheatsheetQuick Git reference for setup, commits, branches, remotes, and safe undos—pair with the full Git tutorials when you want deeper practice.
• HTML CheatsheetQuick reference for HTML5 document structure, text, media, tables, forms, and accessibility basics.
• CSS CheatsheetQuick reference for CSS selectors, the box model, typography, Flexbox, Grid, and responsive layout.
• Networking CheatsheetA practical networking reference covering addresses, ports, DNS, HTTP, and everyday troubleshooting commands.
• Cybersecurity CheatsheetA defensive cybersecurity reference for accounts, everyday threats, device hygiene, and calm incident response.
• Docker CheatsheetPractical Docker CLI and Compose reference for images, containers, Dockerfiles, and cleanup—use alongside the Docker tutorials for step-by-step practice.
• Cloud Computing CheatsheetA provider-agnostic cloud reference for service models, regions, compute, storage, identity, cost, and operations.