I am confused about the use of the <link> and <enclosure> subelements of the <item> subelement.
The difference between the <link> subelements of the <channel> and <item> elements appears clear, but the difference between the <link> and <enclosure> subelements of the <item> subelement are difficult to understand. For example, if your RSS feed contained a long series of <item> subelements with each referring to a different podcast, why would you need both a <link> and <enclosure> for the same <item> subelement.
<channel>
<link></link>
<item>
<link></link>
<enclosure></enclosure>
</item>
</channel>