Buttons

<button type="button" class="btn btn-primary">Primary</button>

Preview	Class
	btn btn-default
	btn btn-primary
	btn btn-success
	btn btn-info
	btn btn-warning
	btn btn-danger
	btn btn-link

Sizes

<p>
  <button type="button" class="btn btn-primary btn-lg">Large button</button>
  <button type="button" class="btn btn-default btn-lg">Large button</button>
</p>
<p>
  <button type="button" class="btn btn-primary">Default button</button>
  <button type="button" class="btn btn-default">Default button</button>
</p>
<p>
  <button type="button" class="btn btn-primary btn-sm">Small button</button>
  <button type="button" class="btn btn-default btn-sm">Small button</button>
</p>
<p>
  <button type="button" class="btn btn-primary btn-xs">Extra small button</button>
  <button type="button" class="btn btn-default btn-xs">Extra small button</button>
</p>

Block buttons

<p>
  <button type="button" class="btn btn-primary btn-lg btn-block">Block level button</button>
  <button type="button" class="btn btn-default btn-lg btn-block">Block level button</button>
</p>

Active / Disabled

<p>
  <button type="button" class="btn btn-primary btn-lg active">Primary button</button>
  <button type="button" class="btn btn-default btn-lg active">Button</button>
</p>
<p>
  <button type="button" class="btn btn-lg btn-primary" disabled="disabled">Primary button</button>
  <button type="button" class="btn btn-default btn-lg" disabled="disabled">Button</button>
</p>