Thanks Kovid, I didn't realize that.
But during installation, besides the 'Calibre' program being copied to the 'Applications' folder, a few hideen folders and files are also created in subfolders of the '~/Library' folder, which is located on the internal hard drive, not on the external SSD.
Such files include:
com.calibre-ebook.ebook-edit.plist
com.calibre_ebook.ebook-viewer.plist
net.kovidgoyal.calibre.plist
Such folders include:
~/Library/Application Support/calibre-ebook.com
~/Library/Caches/calibre
~/Library/Preferences/calibre
Can I miss these small, hidden files and folders and still use the 'Calibre' program copied on the SSD without losing essential parameters when moving to another computer?
Thanks in advance! W.