CSS (Cascading Style Sheets) is a style sheet language used to describe the look and formatting of a document written in HTML (Hypertext Markup Language). CSS is used to specify the layout, colors, fonts, and other design elements of a web page, separating the presentation of a website from its content.
CSS works by matching selectors (such as HTML tags or class names) to specific styles. For example, you can use CSS to specify that all headings on a page should be blue and have a certain font size. The styles are defined in a CSS file, which is linked to the HTML document. When the HTML document is loaded into a web browser, the browser applies the styles specified in the CSS file to the HTML content, determining how the page is displayed.
CSS has a cascading nature, meaning that styles can be inherited from parent elements to child elements. This allows you to create a consistent look and feel throughout a website by defining styles at higher levels and then inheriting and modifying those styles for specific elements as needed.
CSS has become an essential part of web development, enabling developers to create beautiful, responsive, and functional websites.