[OpenLayers-Users] What Does this Documentation Item Mean?

[Arnie Shore]

It's the Icon Constructor definition:

   Constructor
   OpenLayers.Icon

   Creates an icon, which is an image tag in a div.

1.  Re "... which is an image tag ...":  But lots of examples exist for 
which the icon file's address is provided via URL and not an img tag.

2.  Re " ... in a div ... ":  OK, it must be contained within a div. 
But the map must be contained within a div, so isn't this requirement 
redundant?

What am I missing?

(I'm raising these basic points here cuz of the trouble I'm having 
scripting with a custom, non-default icon, and I thought it possibly 
useful to get back to first principles.)

AS