title: How does a dictionary do a fast lookup
body: <p>I am looking at the <code>Item[TKey]</code> source of <code>Dictionary&lt;TKey,TValue&gt;</code> trying to understand the mechanism of storage/retrieval in a dictionary, and why it is faster than just checking each entry one by one.</p>
  
  <p>Where I get confused is in the user of prime numbers in <code>buckets</code> field and the interplay with <code>Entry&lt;TKey,TValue&gt;.next</code>.</p>
  
  <p>Can someone explain to me the logic, or point to a reference where I can understand it.</p>
  
  <p>Thanks.</p>