What is the use of Normalized Email & UserName in .NET core IdentityUser Model?
<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>