What is one key method to optimize images for web use?

Implementing responsive images is a key method to optimize images for web use because it allows images to be displayed correctly across different devices and screen sizes. Responsive images adjust their size and resolution based on the visitor's device, ensuring that a high-quality image is shown on larger screens while serving a smaller, more compressed version to mobile devices. This not only enhances the user experience by providing optimal display of images but also significantly improves loading times and reduces bandwidth usage by avoiding the delivery of unnecessarily large image files.

By using techniques such as the <picture> element or the srcset attribute in HTML, developers can specify different image sources for various screen sizes and resolutions, ensuring that the best format and size are served. This approach helps maintain the quality and responsiveness of web applications while optimizing performance.