What it means in plain language
HTML is a markup language that describes the structure of a web page, including headings, paragraphs, links, forms, images, and semantic elements.
Where it genuinely helps
HTML describes document meaning and structure: headings, paragraphs, forms, images and relationships used by browsers and assistive technology.
What to decide before acting
Choose the semantic element before styling and do not build a button from an arbitrary tag merely because it looks similar.
How to tell whether it works
Validate structure, heading order, form labels, alternative text and behaviour without styles.