title: What is the difference between $filter and facet in Azure Search
body: <p>Quite new to <strong>Azure Search</strong>, and just wondering what is the difference between facet and filter?</p>
  
  <p>Say I have a product table, and it has category and subcategories. If I want to return things under one category, should I use <code>$filter</code> or use facet? What is the difference between these two?</p>
  
  <p>Many Thanks</p>