"The correct answer is Cascading style sheets. Key Points CSS stands for Cascading Style Sheets. CSS is a stylesheet language used to describe the presentation of a document written in HTML or XML (including XML dialects such as SVG, MathML, or XHTML). CSS describes how elements should be rendered on screen, on paper, in speech, or on other media. CSS saves a lot of work. It can control the layout of multiple web pages all at once. External stylesheets are stored in CSS files. CSS allows for separation of content from presentation, which improves content accessibility, provides more flexibility and control in the specification of presentation characteristics, enables multiple pages to share formatting, and reduces complexity and repetition in the structural content. Additional Information CSS has a simple syntax and uses a number of English keywords to specify the names of various style properties. CSS is maintained by the World Wide Web Consortium (W3C), which is the standard organization for the Web. CSS is designed to enable the separation of presentation and content, including layout, colors, and fonts. This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to share formatting, and reduce complexity and repetition in the structural content. CSS can also allow the same markup page to be presented in different styles for different rendering methods, such as on-screen, in print, by voice (via speech-based browser or screen reader), and on Braille-based tactile devices."

Cascading Style Sheet Reason The full form of CSS is Cascading Style Sheet.