1) Bootstrap Pager

Pager is part of Pagination. pager is mainly work of Next & Previous

To use the .pager class in <ul> element.

Example:-

 <ul class="pager">
  <li><a href="#">Previous</a></li>
  <li><a href="#">Next</a></li>
 </ul>

2) Bootstrap Align Buttons

Set the gap in Previos & Next Button.

To use the .previous & .next class to align each button.

Example:-

 <ul class="pager">
  <li class="previous"><a href="#">Previous</a></li>
  <li class="next"><a href="#">Next</a></li>
 </ul>