Missing iCloud documents
Several months ago I had an icon in my Finders Favorites, iCloud. That has changed to iCloud Drive. I had saved about 30 text files in iCloud. Now when I click on the iCloud Drive icon in finder I am asked to upgrade to iCloud Drive, and warned that doing so will delete any documents in iCloud. While talking to Apple Care I went from my iMac to my MacBook Air, opened Finder and found iCloud at the top of the Favorites column. I click on this icon and all my missing txt files appeared. I dragged one to my desktop. I planned to go back to my MBA in an hour or so and drag the remaining files to folder on my HD. After an hour or so the iCloud icon had disappeared in Finder on my MBS and had been replaced with in iCloud Drive icon. Both my Macs are running the latest version of Yosemite 10.10.1.
Where are my files stored in iCloud??
iMac with Retina 5K display, OS X Yosemite (10.10.1), MacBook Air, Apple TV v2