icloud & icloud drive and ipad backups

i wanted to add to the IOS forum, but did not get the chance.
Now that icloud drive is available, I see that you can select icloud drive to keep copies of documents etc - like onedrive, dropbox etc . However, how does the ipad/iphone backup - in the past you chose icloud, but now on the apple site - it says use icloud drive - and once changed cannot go back. I dont have an ipad but a few friends usually ask me about this stuff - so any advice please.

1. ICloud Drive is not yet available for Macs (unless you are testing Yosemite), so unless ALL your devices are on iOS 8 and Yosemite, iCloud Drive is not for you.

2. Once that's established, iCloud Drive works exactly the same as before for iOS backups.The primary difference is that you can now buy additional storage for very reasonable fees if you need to, and you can store any kind of document you like, whereas before you were limited to iWork documents mostly.

Brilliant , thanks for that prompt and clear reply.

Now I understand all the documentation I have been reading , it was not clear that the devices would backup to icloud drive.
Mainly these are people who just have an ipad and windows PC - I notice the windows icloud control panel updated last night - so i guess if you have an icloud account , you can then use on windows and get photostream to sync on all devices - which is how i setup my friends pcs mainly

thanks again