Cheatsheets & references

Fast definitions and practical examples for every course on Free Computer Courses. Use these sheets while you work; open the matching course when you want step-by-step lessons.

Each cheatsheet groups common commands and concepts with a short definition and a copyable example— original reference material written for beginners, not a dump of unexplained snippets.

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• 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.