Part of macOS
coreservicesdApp launching
○ Leave it
Knows which app opens which file, and launches apps.
What it is
Keeps track of installed apps and file types.
If you stop it
macOS starts it again straight away. 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
coreservicesdlsdlaunchservicesdCoreServicesUIAgent
From Procession’s guide, in the words the app shows.