Description according to the netdata project:
netdata is the fastest way to visualize metrics. It is a resource
efficient, highly optimized system for collecting and visualizing any
type of realtime timeseries data, from CPU usage, disk activity, SQL
queries, API calls, web site visitors, etc.
netdata tries to visualize the truth of now, in its greatest detail,
so that you can get insights of what is happening now and what just
happened, on your systems and applications.
On XCP-ng, this package comes with a configuration where the web UI is
disabled. Install netdata-ui for a ready-to-use netdata with web
UI.