what are the relocated items that can appear on the desktop
Finally, after months of waiting, you’ve been able to install Catalina macOS on your Mac. You’ve backed up everything just in case, downloaded the installer from the Mac App Store or the System Preferences pane, followed the steps, and waited for the upgrade to finish… and suddenly you’re in for a surprise: a folder called “relocated items” on the desktop.
What’s that? Why is it there if it wasn’t there before, with Mojave macos? Don’t worry, you didn’t break anything. Most probably, inside that folder you will find macOS configuration files that are no longer compatible . They may also be configuration files for some 32-bit application that has stopped working.

In fact, if you have more than one Mac, a folder of relocated items will appear for each machine you upgrade to Catalina macOS. These are shortcuts, the original directories are in the MacOS UsersShare folder, probably within several folders one inside the other that represent the original path the file was in.
There’s little we can do with these files. If they are needed, the system or application will have regenerated them in their new locations (if necessary). Therefore, unless you locate a file that you know well what it is, the best you can do is to delete those folders and shortcuts you have on your desktop.
On AppleThe iCloud Drive folder sharing feature will be available on Catalina macOS by 2020, confirmed by Apple
You won’t break anything if you do, you’ll simply get rid of configuration files that have become obsolete and in the worst case scenario you’ll have lost some settings. In my case I found a file related to password management that I can’t even see or edit because I don’t have permissions for it. Coincidentally, I had to re-enter my Apple ID password on both my Macs right after the Catalina upgrade.
In other words and to summarize: don’t worry . If in those relocated items you see nothing but cryptic files from system directories, delete them and enjoy all the new features of Catalina macOS.