Forum "Insert Image" & Post Attachment - difference?
 

So when a user is writing a post, they can "Insert Image" from above the editor, or they can add an attachment with the "Manage Attachments".

What's the difference? They can add a photo either way, but the methods are slightly different. I also notice that the "attachments" have a window around them and the "insert images" don't.

I chose not to have thumbnails on my forum, and the attachments are viewed inline.

What's the advantage of having two different methods for uploading photos?