bootstrap display none
snippet in html

bootstrap display inline block

user7297

<div class="d-inline-block"></div>

visibility hidden bootstrap 4

user2705

<div class="visible">...</div>
<div class="invisible">...</div>

bootstrap display none

user3343

<!-- Bootstrap 4 -->
<div class="d-none"></div>

<!-- Bootstrap 3 -->
<!-- <div class="hidden-{screen size}"></div> -->
<div class="hidden-md"></div>

bootstrap hide row

user678

<div class="d-none"></div> for bootstrap 4

is display-block a class

user2544

<span class="d-block p-2 bg-primary text-white">d-block</span>
<span class="d-block p-2 bg-dark text-white">d-block</span>