HTML (HyperText Markup Language) is the text format that describes what is on a web page and what each piece is: this line is a heading, this is a paragraph, this is a link, this is a photo. Every page you open in a browser arrives as HTML first, even when it was produced by a fancy framework.
How HTML marks up a page
HTML wraps content in tags written in angle brackets. A heading looks like <h1>Fresh bread daily</h1>, a link like <a href="/menu">See the menu</a>. Tags nest inside each other to form a tree, which the browser reads top to bottom and turns into the Document Object Model, the live structure that scripts and styles act on.
Some tags carry attributes with extra detail: an image tag has a src for the file and an alt for a text description. The <head> section holds information visitors do not see directly, such as the page title and meta description that search engines show in results. The current standard is the HTML Living Standard maintained by WHATWG, which replaced numbered versions like HTML5.
A worked example: a bakery contact section
A bakery's contact block might use an <h2> for "Visit us", an <address> element for the street location, a <a href="tel:..."> link so phones can dial with one tap, and a <form> with labelled inputs for catering enquiries. None of that sets colours or fonts. It only says what each part means, and that meaning is what screen readers, Google and mobile phones rely on.
Why the structure matters to a business owner
You rarely need to write HTML by hand, since builders and content systems generate it. It still decides things you care about: whether Google understands which text is your main heading, whether a blind visitor can navigate your menu, and whether your phone number is tappable. Styling comes from CSS and behaviour from JavaScript, but both depend on sensible HTML underneath.
Common HTML mistakes
- Picking tags for their look. Using a heading tag just to make text big confuses the outline search engines and assistive tools read.
- Several h1 headings or skipped levels. Jumping from h1 to h4 breaks the logical order of the page.
- Images without alt text. The picture becomes invisible to screen readers and to image search.
- Clickable divs instead of buttons and links. They cannot be reached with a keyboard unless extra work is done.
- Form inputs without labels. Visitors using assistive technology cannot tell which box is for email.
Related terms
- CSS: controls how the HTML looks.
- JavaScript: adds behaviour on top of the HTML.
- Title tag: an HTML element in the head that search results display.
- Web accessibility: largely depends on using the right HTML elements.