What is Sass in the context of Liferay?

Sass, in the context of Liferay, is a CSS preprocessor that enables developers to create dynamic styling for their web applications. It enhances the capabilities of CSS by adding features such as variables, nested rules, mixins, and functions, which allow for more maintainable and organized stylesheets.

Using Sass, developers can write styles in a more intuitive manner, enabling them to easily manage complex styles and reuse code snippets through mixins. This approach promotes efficiency, as it reduces redundancy and allows for easier updates to styling. In Liferay, where custom themes and styles are essential for tailoring user experiences, utilizing Sass is particularly beneficial.

The other options do not pertain to Sass. A JavaScript library for DOM manipulation refers to tools like jQuery, while a video streaming tool has no relation to styling or CSS. A system for managing user data doesn't connect to the preprocessor used for styling web pages. Thus, Sass stands out as the correct answer emphasizing its role as a CSS preprocessor within frameworks like Liferay.