What is markdown in simple terms?

Markdown is a way of writing formatted text using ordinary characters instead of buttons: **asterisks** for bold, # for headings, - for lists. The file stays plain text, and any markdown-aware app renders it with real formatting.

A .md (or .markdown) file is just a plain text file whose content uses markdown syntax. It opens in any text editor — Notepad, TextEdit, VS Code — and renders as a formatted document in markdown viewers, on GitHub, or on a share link.

How do you open a markdown file?

To edit: any text editor. To see it rendered: GitHub or an editor with preview (VS Code: Cmd/Ctrl+Shift+V), or paste it into docs-md.com to view and share it rendered — no install needed.

Is markdown the same everywhere?

The core (headings, emphasis, lists, links, code) is universal, standardized as CommonMark. Most sites add GitHub Flavored Markdown extensions — tables, task lists, strikethrough. Chat apps like Slack and Discord use their own dialects.

What is markdown?

Markdown is a plain-text way to write formatted documents: a few punctuation conventions — **bold**, # headings, - lists — that stay readable as raw text and render as rich formatting.

Markdown is a lightweight markup language created by John Gruber and Aaron Swartz in 2004. Instead of clicking formatting buttons, you type conventions straight into the text — **bold**, # heading, - list item — and any markdown-aware app turns them into formatted output. The design goal, in Gruber's words, was text that's publishable as-is: readable even when it never gets rendered.

You type

# Trip notes

**Flight** lands at *14:30* — then:

1. Pick up the rental car
2. Check in before 18:00

> Confirmation code: `KX-42871`

Readers see

Trip notes

Flight lands at 14:30 — then:

Pick up the rental car
Check in before 18:00

Confirmation code: KX-42871

What is a .md file?

A file ending in .md (or .markdown) is a plain text file written in markdown — nothing more. There's no special format to decode and no app that owns it: it opens in Notepad, renders on GitHub (every repository's README.md is one), and diffs cleanly in version control. That durability is the point — a .md file from 2004 still opens perfectly today.

How do you open and view a markdown file?

To edit: any text editor. To view it rendered: VS Code's built-in preview (Cmd/Ctrl+Shift+V), GitHub, Obsidian — or paste it into the editor on this site to see it rendered instantly and get a shareable link, with no install. From there you can also convert it to PDF or to HTML.

Why did developers and AI tools standardize on markdown?

Because plain text wins everywhere it matters: it works in git, survives every platform, and is trivial for programs to generate. That last property made markdown the native output format of AI assistants — ChatGPT, Claude, and coding agents all emit it, and AI IDEs read and write .md context files. Writing, docs sites, note apps (Obsidian, Notion), forums (Reddit, Discord in dialect form), and READMEs all converged on the same syntax — learn it once, use it everywhere.

How do you learn the syntax?

The core takes ten minutes: skim the cheat sheet for every element with rendered examples, and use the guides when a specific question comes up — checkboxes, line breaks, comments, centering. Chat apps differ: see Discord and Slack.