Can instance grouos a set of can devices, each device can have a can id on that can bus.
Its not entirely unique to a victron system just how can works. Even can bus in vehicles is set up like this.
A short google search would have answered that.
@VWard
Just a warning about AI use. Even to structure posts - it makes them ultra (and unecesarily) long. It is against community guidelines. Please edit it.