Part of macOS
cupsdPrinting
○ Leave it
Runs printing.
What it is
Sends documents to printers and manages print queues.
If you stop it
Printing stops until macOS starts it again. Leave it.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
cupsd
From Procession’s guide, in the words the app shows.