what is the bootstrap loader code example

Example 1: bootstrap loader

<div class="spinner-border text-primary" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-secondary" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-success" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-danger" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-warning" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-info" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-light" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-dark" role="status">
  <span class="sr-only">Loading...</span>
</div>

Example 2: bootstrap loader

<div class="spinner-border" style="width: 3rem; height: 3rem;" role="status">
  <span class="sr-only">Loading...</span>
</div>
<div class="spinner-grow" style="width: 3rem; height: 3rem;" role="status">
  <span class="sr-only">Loading...</span>
</div>