Markdown is a plain-text formatting syntax created by John Gruber in 2004. You write using simple characters — hash marks for headings, asterisks for bold, dashes for lists — and software converts it to formatted HTML. The source remains readable even without rendering.

Writers love Markdown because it keeps hands on the keyboard. No mouse needed to click bold buttons or hunt through menus. Once you learn ten syntax rules, you can format documents faster than in any word processor.

Headings use one to six hash symbols: # H1, ## H2, ### H3. Bold text uses **double asterisks** and italic uses *single asterisks*. Unordered lists start with - or *, and ordered lists use 1. 2. 3.

Links are written as [visible text](https://url.com). Images use the same syntax with an exclamation mark prefix. Inline code uses single backticks, and multi-line code blocks use triple backticks on separate lines.

GitHub renders Markdown in README files, issues, and pull requests. Notion, Obsidian, and Bear support Markdown input. Reddit, Stack Overflow, and Dev.to accept Markdown in posts. Static site generators like Jekyll, Hugo, and Astro build entire blogs from Markdown files.

If you write anywhere on the modern web, learning Markdown is a one-time investment that pays off across dozens of platforms.

Use a live preview editor to see formatting as you type. This catches syntax errors immediately instead of after publishing. Keep a syntax cheat sheet nearby for tables and less common elements.

Separate paragraphs with blank lines. Leave a blank line before headings and lists for reliable rendering across different Markdown flavors. When in doubt, preview before publishing.