To implement responsive images using HTML and CSS, you can follow the steps below. Responsive images are essential for ensuring that your website looks good and performs well on various devices with different screen sizes. 1. Use the `<img>` tag with the `srcset` attribute: The `<img>`` tag is the standard HTML element for displaying images. To make it responsive, you can use the srcset attribute, which allows you to provide multiple image sources at different resolutions or sizes. The browser will then choose the most appropriate image based on the user's device and screen size. 

<img src="default-image.jpg"
     srcset="small-image.jpg 480w,
             medium-image.jpg 768w,
             large-image.jpg 200w"
     alt="Description of the image">
In the example above, we provide three image sources: `small-image.jpg`, `medium-image.jpg`, and `large-image.jpg`. The numbers after the image names (480w, 768w, and 1200w) represent the image widths in pixels. The browser will decide which image to load based on the device's screen width. 2. Set the `sizes` attribute: The sizes attribute is used to provide additional information to the browser about the image sizes. It helps the browser determine the appropriate image to load based on the viewport's size (screen size and resolution). 

<img src="default-image.jpg"
     srcset="small-image.jpg,
             medium-image.jpg,
             large-image.jpg"
     sizes="(max-width: 600px) 480px,
            (max-width: 1024px) 768px,
            1200px"
     alt="Description of the image">
In the example above, we set specific image sizes for different viewport widths using media queries. If the viewport is 600 pixels wide or less, the browser will load the 480 pixels wide image. If the viewport is between 601 pixels and 1024 pixels wide, the 768 pixels wide image will be used. For viewports wider than 1024 pixels, the 1200 pixels wide image will be loaded. 3. Add CSS for responsive behavior: Sometimes, you may want to style the images differently based on the device's screen size. You can achieve this by using CSS media queries. 

/* CSS for small screens (up to 600 pixels) */
@media (max-width: 600px) {
  img {
    max-width: 100%;
  }
}

/* CSS for medium screens (601 to 1024 pixels) */
@media (min-width: 601px) and (max-width: 1024px) {
  img {
    max-width: 80%;
  }
}

/* CSS for large screens (greater than 1024 pixels) */
@media (min-width: 1025px) {
  img {
    max-width: 60%;
  }
}
In the example above, we set different maximum widths for the images based on the screen size using media queries. For small screens, the image will take the full width of its container. For medium screens, it will be limited to 80% of the container width, and for large screens, it will be limited to 60% of the container width. With these steps, you can implement responsive images that adjust according to the user's device and screen size, providing a better user experience on different platforms.