Different ranges can point to one and the same text, but to different XML tags. For example we have three XML-fragments:
<p>text|<strong><em>inner text</em></strong>|text</p>,
<p>text<strong>|<em>inner text</em>|</strong>text</p>, and
<p>text<strong><em>|inner text|</em></strong>text</p>
In all three fragments the ranges point to one and the same text "inner text", but they have different XML-ranges.
The Normalize method transforms the first two ranges to the third one; it moves pointers inside (into the most inner tag).
So, this method is necessary for a user to be sure that he works with a range positioned only on the text but not somewhere between elements in a document.
Example
The following example replaces the selected text with a new value.
C1TextRange range = _editor.Selection.Clone();
range.Text = value;
//after inserting text we must collapse selection to the end
range.Normalize();
range.Start.MoveTo(range.End);
range.Select();
