What does CSS stand for?

CSS stands for Cascading Style Sheets. This term reflects its primary purpose in web development, which is to define the presentation and layout of HTML elements in a web document. The "Cascading" aspect indicates how styles can cascade or inherit from one another, allowing for a hierarchical system where styles can be overridden based on their specificity and importance. This helps developers create responsive, attractive web pages with consistent styling across various elements.

Understanding that "Cascading Style Sheets" effectively conveys the function and ordered nature of styles can clarify how CSS operates in conjunction with HTML to enhance user experience and design. The other options, while they may seem plausible, do not accurately describe the function or definition of CSS in web design.