Media Queries are a powerful feature in CSS that allow web developers to create responsive designs. They enable the website to adapt its layout and style based on the characteristics of the device being used, such as screen size, resolution, and orientation. This means that a website can look great on both a smartphone and a desktop computer without needing separate versions. By using Media Queries, developers can apply different styles for different devices. For example, they might increase font sizes for larger screens or stack images vertically on smaller ones. This flexibility ensures a better user experience, making websites more accessible and visually appealing across various devices.