Heading hierarchy
Heading hierarchy is the use of `<h1>`–`<h6>` elements to express page and section relationships; levels should represent content structure rather than visual size alone.
Detailed explanation
Screen-reader users can navigate by heading through browser and screen-reader commands. Clear, descriptive headings make sections easier to find; missing headings, empty headings, and levels chosen only for styling can obscure the intended relationships. A skipped numeric level is a review signal rather than an automatic failure in isolation.
WCAG 2.1 SC 1.3.1 (Info and Relationships) at Level A requires programmatic heading structure. SC 2.4.6 (Headings and Labels) at Level AA additionally requires that the heading text be descriptive of the content that follows.
How this applies to Shopify stores
Shopify theme styling and merchant-configured sections can produce missing, empty, or unexpectedly ordered headings. AccessComply can report selected heading-structure findings per reached page; a skipped numeric level is a review signal, and the correct hierarchy depends on the content relationships.
What merchants should check next
Treat this term as a practical audit prompt, not just a definition. Check the storefront pages where the concept shows up in real customer journeys: product discovery, add-to-cart, cart drawer, checkout handoff, account login, and support contact flows. If the issue affects code, verify the rendered HTML and computed browser output after the theme change. If it affects copy or media, keep the merchant-facing wording accurate and easy to maintain.
Primary source: w3.org