title: What is the use of Normalized Email & UserName in .NET core IdentityUser Model?
body: <p>When I use <code>IdentityUser</code> model in <em>Asp.Net</em> <code>Identity</code> with <code>EntityFramework</code>, it creates some standard fields in the database. All the fields are self explanatory except for the below two fields.</p>
  
  <ul>
  <li><code>NormalizedUsername</code> - Which contains the uppercase value of the Username</li>
  <li><code>NormalizedEmail</code> - Which contains the uppercase value of the Email</li>
  </ul>
  
  <p>My doubts are: </p>
  
  <ol>
  <li>Why do we need these Normalized fields? Where does it get used?</li>
  <li>What is the purpose of persisting it in the database?</li>
  </ol>