Answers for "image grid bootstrap"

responsive image in bootstrap

<img src="..." class="img-responsive">

bootstrap img src

<img src="..." class="rounded mx-auto d-block" alt="...">

img class bootstrap

<!-- Circuler Image -->
 <img src="cinqueterre.jpg" class="img-circle" alt="Cinque Terre"> 
 
<!-- Image With some border-raduis property  -->
 <img src="cinqueterre.jpg" class="img-rounded" alt="Cinque Terre"> 
 
<!-- Image like thumbnail  -->
 <img src="cinqueterre.jpg" class="img-thumbnail" alt="Cinque Terre">

background image for div in grid system bootstrap

.img {
    margin-right: -15px; // Remove right gap
    margin-left: -15px;  // Remove left gap
    padding-bottom: 62.5%; // ratio is 16:10
    background-position: 50% 50%;
    background-repeat: no-repeat;
    background-size: cover;
}