Markdown Glossary

The descriptive text inside square brackets of an image tag. Screen readers announce this text and it displays when the image fails to load.

A link that jumps to a specific heading within the same page. Created by linking to a heading's auto-generated ID.

A GFM feature that automatically converts bare URLs into clickable hyperlinks without requiring square bracket/parenthesis syntax.

The character used to create inline code and fenced code blocks. Located below Escape on most keyboards.

A styled blockquote used to draw attention to specific content. GitHub uses [!NOTE], [!WARNING], etc. Obsidian uses [!info] syntax.

The standardized specification for markdown syntax. Defines the unambiguous rules for parsing headings, emphasis, links, code, lists, and other core elements.

An extended markdown feature that pairs terms with definitions. Some processors support term on one line and : definition on the next.

Special characters that mark the start and end of formatted text — asterisks for emphasis, backticks for code, tildes for strikethrough, pipes for tables.

Italic text created with single asterisks or underscores. The general term for text styling that draws attention — includes both italic and bold.

A backslash placed before a special character to display it literally instead of triggering formatting.

Markdown features beyond the original spec — tables, footnotes, task lists, strikethrough, and definition lists. Support varies by parser.

A code block delimited by triple backticks or tildes on separate lines. Supports a language identifier for syntax highlighting.

A reference marker that links to an annotation at the bottom of the document. Supported in GFM, PHP Markdown Extra, and Obsidian.

A YAML, TOML, or JSON block at the top of a markdown file that stores metadata like title, date, tags, and author.

GitHub Flavored Markdown — GitHub's extension of CommonMark that adds tables, task lists, strikethrough, autolinks, and alert callouts.

The creator of markdown. Published the original specification and Perl script in 2004 on his Daring Fireball blog. The name "markdown" was chosen to contrast with HTML markup.

A forced line break within a paragraph, created by ending a line with two trailing spaces or a backslash. Distinct from a soft break.

Most markdown processors allow raw HTML tags inline. Useful for elements markdown doesn't support natively — details, kbd, sub, sup, and more.

Short code snippets within a sentence wrapped in single backticks. Renders in a monospace font with a subtle background.

A popular Ruby-based static site generator that processes markdown files into websites. Powers GitHub Pages with Liquid templates and YAML front matter.

A data format often embedded in markdown via fenced code blocks. Also used in front matter by some static site generators as an alternative to YAML.

A fast math typesetting library used by GitHub, Obsidian, and other platforms to render LaTeX expressions in markdown.

An HTML tag used in markdown to visually represent keyboard keys. Renders with a bordered key-cap style on GitHub.

A typesetting system for mathematical notation. Many markdown processors support LaTeX math via $inline$ and $$display$$ syntax.

A tool that checks markdown files for style and syntax issues — inconsistent headings, trailing whitespace, or broken links. Popular ones include markdownlint.

A lightweight markup language created by John Gruber in 2004 that converts plain text with formatting symbols into HTML. The default output format for most AI models.

An extended markdown format that allows JSX components to be embedded directly in markdown files. Used by Next.js, Docusaurus, and other React frameworks.

A diagramming language rendered natively on GitHub. Supports flowcharts, sequence diagrams, Gantt charts, pie charts, and more.

A list item containing a sub-list, created by indenting child items with 2-4 spaces. Works for both ordered and unordered lists at multiple levels.

A knowledge-management app using markdown as its native format. Extends standard syntax with wiki links, callouts, and embedded transclusions.

A numbered sequence of items. The parser auto-numbers regardless of input values — all items could be "1." and still count correctly.

The default block element in markdown. Any text not preceded by a special character becomes a paragraph. Separate paragraphs with a blank line.

Software that reads markdown syntax and converts it into HTML. Common parsers include markdown-it, remark, marked, unified, and pandoc.

The character used as a column delimiter in markdown tables. Each row is a line of pipe-separated values with a hyphen separator row for the header.

A condensed cheat sheet showing all markdown syntax at a glance — typically a table of feature names, syntax, and notes. Essential for learning markdown fast.

Another name for a blockquote — text prefixed with > that renders as indented, visually distinct content. Can be nested with multiple > characters.

HTML tags written directly in markdown. Most processors pass allowed tags through to output unchanged — useful for elements markdown lacks.

A two-part link syntax separating display text from URL. Keeps source cleaner for documents with many links.

The component that takes parsed markdown tokens and produces final HTML output. Can be customized to add classes, attributes, or wrap elements differently.

An alternative heading syntax using underlines instead of hashes. A line of = creates H1, a line of - creates H2. Valid CommonMark but less common.

The URL-friendly ID auto-generated from a heading — lowercase, spaces to hyphens, special characters removed. Used for anchor links within documents.

Colored code formatting inside fenced code blocks activated by specifying a language. Powered by libraries like Shiki, Prism, or highlight.js.

A checklist with - [ ] unchecked and - [x] checked syntax. GitHub renders interactive checkboxes in issues and pull requests.

The formal name for a horizontal rule. Created with three or more hyphens, asterisks, or underscores. Separates sections visually.

A JavaScript ecosystem for processing markdown, HTML, and natural language. The remark and rehype plugins are built on unified's AST pipeline.

A bullet-point list created by starting each line with a dash, asterisk, or plus. Markers vary by nesting depth — disc, circle, or square.

Text rendered exactly as typed with no formatting. Code spans and code blocks produce verbatim output — special characters display literally.

Visual Studio Code — a widely-used editor with built-in markdown preview, syntax highlighting, and extensions for linting and table formatting.

Spaces, tabs, and blank lines that control markdown structure. Trailing spaces trigger line breaks, blank lines separate paragraphs, leading spaces create indentation.

A double-bracket link syntax used by Obsidian, Notion, and wiki systems to link between documents. Not part of standard markdown.

The stricter XML-based variant of HTML. Some markdown processors output XHTML-compliant markup with self-closing tags like <br /> and <hr />.

Cross-site scripting — a security vulnerability relevant to markdown because raw HTML is allowed. Renderers must sanitize output to prevent script injection.

A human-readable data format used for front matter in markdown files. Stores metadata like title, author, date, and tags at the top of a file.

A YAML block at the top of a markdown file between --- delimiters. Static site generators use it to define page metadata, layout, and routing.

An invisible Unicode character sometimes used to break markdown formatting without a visible backslash — prevents **text** from bolding silently.

A knowledge management method using small, interlinked notes — markdown is the preferred format. Apps like Obsidian and Logseq are built on this principle.