What is the difference between pagination and pager

Pagination
Pagination is defined as when we are having a website with lots of pages pagination is created

<ul class= "pagination">
  <li><a href="#">1</a></li>
  <li><a href="#">2</a></li>
  <li><a href="#">3</a></li>
  <li><a href="#">4</a></li>
  <li><a href="#">5</a></li>
</ul>

Pager
Pager is defined as creating the previous and next page buttons

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