Part of macOS
DockThe Dock
○ Leave it
Draws the Dock, Launchpad, Mission Control and desktop spaces.
What it is
Besides the Dock itself, it runs Mission Control, Spaces and app switching.
If you stop it
The Dock disappears for a moment and macOS restarts it. 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
Dock
From Procession’s guide, in the words the app shows.