What exactly is podcasting? Ever since I heard that term it just sounded like a trendy way to say shit you download automatically through RSS/Atom or call home

What exactly is podcasting? Ever since I heard that term it just sounded like a trendy way to say shit you download automatically through RSS/Atom or call home mechanisms. Since updates are a form of media, doesn't Windows Update fall under this term and therefore under this patent? It provides episodic content, ie patches, some that depend on others.