Aspect ratio to get consistently responsive images and iframes. Coupled with Image style. And to fix layout reflow and excessive height issues. <a href="@dimensions" target="_blank">Image styles and video dimensions</a> must <a href="@follow" target="_blank">follow the aspect ratio</a>. If not, images will be distorted. Use fixed ratio (non-fluid) to avoid JS works, or if it fails Responsive image. Fixed ratio means, all images from mobile to desktop use the same aspect ratio. Fluid means dimensions are calculated and JS works are attempted to fix aspect ratio. <a href="@link" target="_blank">Learn more</a>, or leave empty to DIY (such as using CSS mediaquery), or when working with multi-image-style plugin like GridStack.