title: what's sort rule in relate to StringComparison
body: <p>I'm new to C#, just a question on StringComparison. We know that StringComparison has  Ordinal, OrdinalIgnoreCare etc. And some docs say :</p>
  
  <p><strong><em>Ordinal :Compares strings using ordinal (binary) sort rules</em></strong></p>
  
  <p>but I don't understand how sort can relate to string comparsion, don't we just compute ASCII for each character to see if they match? for example, if we code:</p>
  
  <pre><code>string s1 = "Hello";
  string s2 = "HELLO";
  
  if (s1.Equals(s2, StringComparison.Ordinal)) {
     ...
  }
  </code></pre>
  
  <p>and if we want to compare s1 with s2, the first char "H" is the same. the next char of s1 is e with ASCII of 101 and 'E' is 69, 101 doesn't equal 69, so s1 is not the same as s2, so there is no sorting thing involved here?</p>