Text elements and structure

Headings and paragraphs are the two tags you'll use constantly. HTML has six heading levels, from most to least important:

<h1>Page title</h1>
<h2>Section title</h2>
<h3>Subsection title</h3>

Use exactly one <h1> per page -- it should describe what the whole page is about. Use <h2> and below for everything after that.

Paragraphs and line breaks

<p>This is a paragraph. It can span as many
lines in your code as you want -- the browser
collapses them into one flowing block of text.</p>

Don't use multiple <br> tags to create spacing between paragraphs -- that's what CSS margins are for. Save <br> for genuine line breaks inside content, like a mailing address.

Bold and italic

<p>This is <strong>important</strong> and this is
<em>emphasized</em>.</p>

Use <strong> and <em> rather than the older <b> and <i> -- they carry meaning, not just a visual style, which matters for screen readers.