Can I access icloud from ipad

You access the iCloud data through the appropriate app (I.e. Contacts, Notes, Pages, Photos etc), you can't use iCloud.com if that's what you mean.

So if my photos are being automatically backed up from my iPhone, why can't I see them on my iPad. I thought they are supposed to be visible across all my devices if they are stored in the cloud. Is iCloud the cloud being referred to in this instance or it there some other cloud?

I can see all my photos in dropbox from any device