What is the purpose of media queries in CSS?

Media queries are a fundamental feature in CSS that allow developers to apply styles based on specific characteristics of the device or viewport, such as its width, height, resolution, and orientation. This capability is essential for creating responsive designs that adapt to different screen sizes and device capabilities. By utilizing media queries, styles can be tailored to provide optimal viewing experiences across a range of devices, from desktops to tablets to smartphones.

For example, a media query can be set to change the layout of a webpage if the screen width is less than 600 pixels, which is crucial for ensuring that content remains accessible and visually appealing on smaller devices. This adaptability enhances usability and improves the overall user experience by making sure that web applications look good and function well on various platforms.