HTML
HyperText Markup Language – the markup language for web pages. HTML defines structure and content: headings, paragraphs, links, images, forms and more.
HTML is the foundational language of the web. Every website, web app and many emails are built on HTML. Since Tim Berners-Lee’s first site in 1991 it has evolved from simple text documents to the semantic, media-rich HTML5 that structures billions of pages today. Using HTML well is essential for SEO, accessibility and performance.
What is HTML?
HTML (HyperText Markup Language) is the standard markup language for structuring web pages. HTML documents are built from nested elements (tags) that describe content semantically: headings (h1–h6), paragraphs (p), links (a), images (img), lists (ul/ol), forms (form), tables (table) and more. HTML5 adds semantic elements (header, nav, main, article, section, footer), media (audio, video, canvas), APIs (geolocation, storage, workers) and form features (date, email, range inputs). HTML defines structure; CSS handles styling; JavaScript handles behaviour.
How does HTML work?
The browser receives an HTML document, parses it and builds the DOM (Document Object Model) – a tree of all elements. It uses semantic tags: h1 as main heading, nav as navigation, main as main content. CSS is applied to the DOM; JavaScript can change it. Screen readers use HTML semantics for accessibility; search engines use them to understand structure. Good semantic HTML is the basis for SEO and accessibility.
Practical Examples
Semantic page structure: header, nav, main, article and footer for clear sections.
Responsive images: The picture element with srcset serves different sizes and formats (WebP, AVIF) by screen – saves bandwidth and speeds load.
Forms: HTML5 input types (email, tel, date, number) give built-in validation and platform-appropriate keyboards on mobile.
Open Graph: Meta tags in the head define how the page appears when shared (title, description, image).
Typical Use Cases
Websites and web apps: The structural base of every web presence
Email marketing: HTML emails for newsletters and transactional mail
SEO: Semantic HTML helps search engines understand and rank content
Accessibility: ARIA and semantic elements make sites usable for everyone
Documentation: HTML for technical docs, manuals and help
Advantages and Disadvantages
Advantages
- Universal: HTML works in every browser on every device
- Semantic: Correct elements describe meaning, not just layout
- SEO: Search engines use HTML structure in ranking
- Accessible: Semantic HTML is the base for screen readers and assistive tech
- Stable: HTML is backward compatible – old sites still work
Disadvantages
- No styling: You need CSS for design, JavaScript for interactivity
- Static: HTML alone can’t generate dynamic content – needs server or JS
- Validation: Browsers render invalid HTML too, which can cause inconsistent behaviour
- Forms: Complex validation usually needs JavaScript; HTML5 validation is limited
Frequently Asked Questions about HTML
Do I need to learn HTML if I use React/Vue?
What is semantic HTML and why does it matter?
Is HTML hard to learn?
Related Terms
Want to use HTML in your project?
We are happy to advise you on HTML and find the optimal solution for your requirements. Benefit from our experience across over 200 projects.