Check out example codes for "bootstrap toast". It will help you in understanding the concepts better.

Code Example 1

<div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
  <div class="toast-header">
    <img src="..." class="rounded mr-2" alt="...">
    <strong class="mr-auto">Bootstrap</strong>
    <small>11 mins ago</small>
    <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
      <span aria-hidden="true">×</span>
    </button>
  </div>
  <div class="toast-body">
    Hello, world! This is a toast message.
  </div>
</div>

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