Relocated Items on Mac

Hi all,
Each time I update my Mac to a new version of Mac OS, I end up with a new folder on ,my desktop called Relocated Items.
I have no real idea of what the files inside the folder are, or why the system has apparently relocated them, let alone decided to put this folder on my desktop.
Does anyone understand what this is about better than I do?
And is it safe for me to delete this folder, or at least to move it somewhere out of sight?
Thanks,
Dave