bootstrap display none and display block code example
Example 1: bootstrap display block
<div class="d-block"></div>
d-block = for displaying
d-none = to hide
Example 2: bootstrap display none
<!-- Bootstrap 4 -->
<div class="d-none"></div>
<!-- Bootstrap 3 -->
<!-- <div class="hidden-{screen size}"></div> -->
<div class="hidden-md"></div>