So, then I misunderstand something. What is the difference between framesets and iframes with respect to the advantages/disadvantages page I linked to (Link)?

They both call on/hold other documents, don't they? In both the LCARS and the frameset examples that you made, the main page links to other documents which hold no links themselves.

So, in both cases I see the three main advantages that are listed on the website I linked to:
1. Frames are one way to make your site easy to navigate because you can have a constantly visible navigation menu - and easy navigation is one of the most important aspects of website design.
2. Frames can make your site faster because you can include the site theme (images, logo, etc..) and the navigation menu in frames that do not have to download each time a visitor looks at a new page. Only the contents page changes.
3. Using frames can make site maintenance easy, especially if you have a large site. If for example you want to add a new page that is linked from the other pages on your site, you simply add a link on your navigation menu; you do not have to add links on each and every page.

And the three main disadvantages:
1. The original argument was that not all browsers support frames, but this must be a very small percentage now. You can get around this by including a area below your frameset. In this noframes area you can include information such as a simple navigation menu and a "Sorry your browser does not support frames" statement - OR if you want you can have a separate version of your website for non-frames browsers but be prepared to do twice as much work maintaining the site.
2. Search engines treat frames as hyperlinks to other pages, so if for example they manage to spider the frame containing your menu, they pages they index will be indexed but without the surrounding frames. If someone finds one or your pages on a search engine they will not be able to navigate around your site.
3. The most important disadvantage is that it is difficult to link to a particular page on your site other than the page containing the frames (usually the homepage) - this is a big disadvantage if you use email to market your site and you want to link to different parts of your web site.

Or am I completely missing something here?