Part of macOS
mdmclientDevice management
○ Leave it
Applies settings from the organisation that manages this Mac.
What it is
If your Mac is managed by work or school, this applies their settings and apps.
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
mdmclientManagedClientManagedClientAgentmanagedeventsdmanagedappsdmanagedappdistributiondmanagedappdistributionagentDeviceConfigurationAgentdeviceconfigurationd
From Procession’s guide, in the words the app shows.