You can look at it like this:
Frame forwarding is equivalent of loading a URL in a 100% frame, so you have your 'custom' header information. Using html code should be something like this:
<title> your title </title>
<frameset rows="100%,*" border="0">
<frame src="your.URL.com" frameborder="0">
<frame frameborder="0" noresize>
Location forwarding works just like meta redirect, it redirects your browser to another URL.
Frame forwarding, also called 'masked forwarding', is not such a good thing for SE optimization, search engines can't quite interpret it that good, so only first page will be indexed.
I think this will be technical enough for you..