What is the difference between HTML and CSS?

Hypertext Markup Language (HTML) provides the raw structure and text content of a web page, whereas Cascading Style Sheets (CSS) determines how that content is visually styled and arranged. HTML defines elements like paragraphs, headings, and buttons, while CSS controls their colours, fonts, margins, and screen layouts across different devices.

Can a website work without CSS?

Yes, a website can function without Cascading Style Sheets (CSS), but it will display as plain text and unstyled content aligned to the left side of the screen. Users can still click links and read text, but the site lacks visual layout, custom typography, brand formatting, and mobile responsiveness.

What does cascading mean in CSS?

The term cascading refers to the specific set of rules browsers use to resolve conflicts when multiple style instructions apply to the same element. Cascading Style Sheets (CSS) determines priority based on rule specificity, source order, and inheritance, ensuring that the most specific or recently defined style takes precedence.

Web Development

CSS

Cascading Style Sheets (CSS) is the web language that controls how a web page looks, managing visual features like colours, fonts, layout, and responsiveness across different screen sizes.

also called: Cascading Style Sheets

// definition

Cascading Style Sheets (CSS) is a rule-based style sheet language used to describe the visual presentation of documents written in markup languages such as Hypertext Markup Language (HTML). A CSS file consists of selectors that target specific elements in the document structure, combined with declaration blocks that define visual properties like colour, margins, font sizing, and layout positioning. Browsers read these style sheets to render visual interfaces on digital screens.

While HTML provides the structural skeleton and content of a web page, CSS controls the aesthetic appearance and spatial arrangement of those structural elements. Unlike JavaScript, which introduces dynamic behaviour and logical interactivity to a web page, CSS focuses strictly on static visual styling and responsive layout adaptations. Separating content structure from visual design allows developers to maintain consistent presentation across an entire website through centralized style rules.

// why it matters

Using Cascading Style Sheets (CSS) enables a business to separate visual design from underlying content, significantly reducing software development overhead. Updating a single centralized CSS file instantly modifies the appearance of thousands of web pages across an entire domain, preventing redundant code and decreasing long-term maintenance costs. Efficient style sheet architecture improves website loading performance, which directly enhances user retention and accessibility compliance. Responsive design capabilities allow a single code base to deliver adapted user interfaces for mobile, tablet, and desktop screens, eliminating the expense of building distinct websites for different devices.

// example

A developer wants to make every button on a website blue with white text and rounded corners. Instead of styling each element individually, the developer writes a single Cascading Style Sheets (CSS) rule targeting the button class. The rule sets the background colour property to blue, text colour to white, and border radius to five pixels. The web browser reads this single rule and applies the specified design styling across every button on the entire website automatically.

Questions and Answers

What is the difference between HTML and CSS?: Hypertext Markup Language (HTML) provides the raw structure and text content of a web page, whereas Cascading Style Sheets (CSS) determines how that content is visually styled and arranged. HTML defines elements like paragraphs, headings, and buttons, while CSS controls their colours, fonts, margins, and screen layouts across different devices.
Can a website work without CSS?: Yes, a website can function without Cascading Style Sheets (CSS), but it will display as plain text and unstyled content aligned to the left side of the screen. Users can still click links and read text, but the site lacks visual layout, custom typography, brand formatting, and mobile responsiveness.
What does cascading mean in CSS?: The term cascading refers to the specific set of rules browsers use to resolve conflicts when multiple style instructions apply to the same element. Cascading Style Sheets (CSS) determines priority based on rule specificity, source order, and inheritance, ensuring that the most specific or recently defined style takes precedence.