HTML structure helps people and software understand how content is organised. A large bold sentence may look like a heading while remaining an ordinary paragraph. A visually tidy grid may be a data table or simply a layout.
Choose elements according to the information they contain. CSS can then control their appearance without taking away the underlying relationships.
Build a useful heading hierarchy
Use headings to identify the page’s subject and its sections. An article can have its main heading, followed by H2 sections and H3 subsections. Related-content headings should not make the main article’s structure confusing.
<h1>Running shoe sizing</h1>
<h2>Measure your foot</h2>
<h3>Length and width</h3>
<p>Record both measurements before comparing the size chart.</p>
<h2>Compare the size chart</h2>
Pick the level according to the relationship, then style it. Choosing H4 solely because its default font is smaller can produce an awkward outline.
Multiple H1 elements are not an automatic ranking penalty. The practical check is whether the page’s main subject and section relationships are clear. A heading-count warning needs inspection before it becomes a development requirement.
Use lists where the relationship is a list
An ordered list suits steps whose sequence matters. An unordered list suits a set of options or related items. Each item belongs in an li element.
<ol>
<li>Open the page.</li>
<li>Inspect the document request.</li>
<li>Record its response status.</li>
</ol>
Navigation can also use a list of links. The list expresses the collection; the anchors provide the destinations. The internal-link guide covers those destinations separately.
Reserve tables for tabular data
A size chart is tabular because each value belongs to a row and column relationship. Use header cells to identify what the values mean, and provide a caption when it helps explain the dataset.
<table>
<caption>Example shoe measurements</caption>
<thead><tr><th scope="col">Size</th><th scope="col">Length</th></tr></thead>
<tbody><tr><th scope="row">Example A</th><td>26 cm</td></tr></tbody>
</table>
Do not use a table merely to place two unrelated content blocks side by side. CSS layout is better suited to that job. Test real data tables on narrow screens so columns remain accessible.
Understand generic containers
A div groups content without assigning it a specific section meaning. A span groups phrasing content within a line. Their default display behaviour differs, although CSS can change it.
A class can identify several related elements for styling or scripts. An ID should identify a unique element in the document. Repeated IDs can make anchors and script targeting unreliable.
Check the generated page
Inspect the current DOM and compare it with the expected content structure. Visual editors can add wrappers or choose elements differently from the authoring interface. Check the actual heading levels, list items, and table headers.
These are structure and accessibility checks. They do not become Core Web Vitals improvements simply because they involve HTML. Keep the ticket tied to the observed problem.
For teams building shared components, my developer SEO training connects semantic markup with practical tests. A technical SEO audit can then identify which templates repeat the same structural issue.