jigdo have 10 DVDs, and HTTP/FTP only 3

[berenger.morel@neutralite.org]

Hi.

I was intrigued few days ago to notice the 10 DVDs available from 
jigdo.
In my memory, debian was only 3 DVDs... but I thought that it was 
because stuff were bigger than before, or that there could be more 
packages.

Now, trying to fetch the hashes, I used the FTP/HTTP page, and there 
are only 3 DVDs. I guess those are not the same ones, so those hashes 
are not usable, but it's not my question.

What is the content difference between jigdo and http ISOs? ( I know 
what is jigdo and how it works, my question is about the content of the 
ISOs. )