HTML, CSS and DHTML

HTML, the HyperText Markup Language, is the standard language used to structure content on the World Wide Web. A web page is a plain-text document in which tags mark up the meaning of each part: headings, paragraphs, lists, links, images, and so on. A web browser reads this markup and renders it into the visible page. Hypertext refers to the links that connect documents, allowing a reader to move from page to page across the web. HTML has evolved through several versions that added and refined its elements.

While HTML defines structure, presentation is the job of CSS (Cascading Style Sheets). CSS rules describe how elements should look — their colours, fonts, spacing, and layout — and keep this styling separate from the content. Separating structure from presentation makes pages easier to maintain, lets a single style sheet control the appearance of many pages, and allows the same content to be presented differently on different devices.

DHTML, or dynamic HTML, is not a separate language but a term for combining HTML, CSS, and a scripting language, usually JavaScript, to make pages that change in response to user actions without reloading. Scripts can alter the document, respond to clicks and key presses, and update styles on the fly. Related server-side and scripting technologies such as CGI and ASP generate pages dynamically before they reach the browser, and features like inline frames let one document embed another. Together these technologies form the foundation of building web pages.

Frequently asked questions

What is the difference between HTML and CSS?

HTML structures the content of a page with tags for headings, paragraphs, links, and more, while CSS controls how that content looks, such as its colours, fonts, and layout.

What is DHTML?

DHTML, or dynamic HTML, is a term for combining HTML, CSS, and scripting such as JavaScript to make pages that respond to user actions and change without reloading.

Why keep style separate from content?

Keeping styling in CSS rather than in the markup makes pages easier to maintain, lets one style sheet control many pages, and allows the same content to adapt to different devices.