HTML 4.0 (the predecessor of 4.01) introduced something called
frames, which split the browser's viewport up into different
sections, each displaying a different webpage. It was a good
idea in concept, but the execution left a few things to be
desired. Amongst the litany of woes: Using the back button on a
browser in frames tended to be unpredictable, depending on what
frame was loaded when. You could not bookmark a specific set of
pages in the frameset's, only the default set. Accessibility for
the disabled was severely compromised. Printing frames could
also wasteful, as you might find yourself printing all pages
displayed in the browser. Viewers would have to download
multiple pages: the page defining the frames, and all pages
displayed by the frames. Not all browsers during frames' heyday
supported frames, so you had to code a no-frames version of your
webpage. So why were they ever used? If you had a part of a
webpage (usually the navigation) that you used over and over
again, a frameset allowed you to p