What do CSS selectors do?

CSS selectors are fundamental components of CSS that are used to apply styles to specific elements within an HTML document. By using selectors, developers can target and manipulate the appearance of elements such as text, images, or entire sections of a webpage. This enables a high degree of control over how content is presented to users.

When a selector is matched to an element, the styles defined in the CSS rules are applied to that element. For instance, if a class selector corresponds with a series of HTML elements, any styling defined for that class will be reflected in those elements when rendered on the page. This mechanism allows for dynamic styling based on both the structure of the HTML and the intent of the design.

The other choices do not accurately describe the function of CSS selectors. Defining HTML tags pertains to the structure of HTML itself, rather than how styles are applied. While importing styles may involve using the @import rule or link tags in HTML, it does not relate to the concept of selecting elements. Lastly, creating new HTML elements involves JavaScript or other HTML methods and does not fall under the functionality of CSS selectors, which are solely focused on styling existing elements.