Downarchive--How Does It Work?

I was recently looking for a science program broadcast either on NGC or
the Sci Channel two years ago on DVD or a rebroadcast. It was produced
by the BBC in 2004. I discovered a site called downarchive that has it.
The site isn't exactly clear, at least, upon my initial read, how this
works. The program of interest, Light Fantastic, is in four 50 minute
segments. Each segment looks like 6-8 downloads. There's a free version
of the download software, and it looks like one subscribes to this
download service for periods of 30, 90, 180 or 365 days at a cost that
may be in pounds. Maybe their s/w pieces the individual downloads into
one 50 min DVD file which can be burned onto a DVD disk?

W. eWatson