What is a "Media Query" in CSS?

A "Media Query" in CSS is a powerful feature that allows developers to apply specific styles to a web page based on various characteristics of the user's device, such as screen size, resolution, and orientation. This responsive design technique ensures that a website looks good and functions well on a wide range of devices, from desktop computers to tablets and smartphones.

By utilizing media queries, designers can set certain styles for different conditions, allowing for a more tailored user experience. For instance, a developer might specify that a particular layout should change when the viewport is narrower than a certain width, enabling a flexible design that adapts to user needs.

The other options presented do not accurately describe what a media query is. Editing images pertains to image manipulation tools, while scripts for enhancing website speed focus on performance optimizations rather than style application. Additionally, plugins for animations are related to adding dynamic visual effects, which is different from the core purpose of media queries in managing styles based on device characteristics.