Images in Bootstrap are made responsive with .img-fluid. max-width: 100%; and height: auto; are applied to the image so that it scales with the parent element.
SVG images and IE 10
In Internet Explorer 10, SVG images with .img-fluid are disproportionately sized. To fix this, add width: 100% \9; where necessary. This fix improperly sizes other image formats, so Bootstrap doesn’t apply it automatically.
In addition to our border-radius utilities, you can use .img-thumbnail to give an image a rounded 1px border appearance.