A button is a good way to add a "call-to-action". Several button styles are available.

The bigger button should be used in main body area while the smaller button should be used in the sidebar area.

Default

Standard button for "call-to-action". 

<a href="#" class="btn btn-default">Default button</a>
<a href="#" class="btn btn-default btn-sm">Default button</a>

Secondary

Use secondary button when two buttons are needed for a piece of information and one of them is the secondary link. Also use the secondary button when it provides better contrast against the background color/image.

<a href="#" class="btn btn-secondary">Secondary button</a>
<a href="#" class="btn btn-secondary btn-sm">Secondary button</a>

Anchor

For links to anchors on the same page. Use sentence case for button label. 

Anchor buttons should go immediately below the page title and below the page lead paragraph and be left-aligned.

<p><a class="btn btn-default btn-xs mr-2 mb-2" href="#">Anchor button 1</a> <a class="btn btn-default btn-xs mr-2 mb-2" href="#">Anchor button 2</a></p>

Deprecated button

Avoid using the purple button as it's being phased out.