<button class="btn btn-secondary btn-sm m-1" type="button" data-toggle="tooltip" data-placement="top" title="Tooltip on top">
  Tooltip on top
</button>
<button class="btn btn-secondary btn-sm m-1" type="button" data-toggle="tooltip" data-placement="right" title="Tooltip on right">
  Tooltip on right
</button>
<button class="btn btn-secondary btn-sm m-1" type="button" data-toggle="tooltip" data-placement="bottom" title="Tooltip on bottom">
  Tooltip on bottom
</button>
<button class="btn btn-secondary btn-sm m-1" type="button" data-toggle="tooltip" data-placement="left" title="Tooltip on left">
  Tooltip on left
</button>
<button class="btn btn-secondary btn-sm m-1" type="button" data-toggle="tooltip" data-html="true" title="&lt;em&gt;Tooltip&lt;/em&gt; &lt;u&gt;with&lt;/u&gt; &lt;b&gt;HTML&lt;/b&gt;">Tooltip with HTML</button>